165279178649025 has 135 divisors (see below), whose sum is σ = 356147253397881. Its totient is φ = 75554344676160.

The previous prime is 165279178648993. The next prime is 165279178649041. The reversal of 165279178649025 is 520946871972561.

The square root of 165279178649025 is 12856095.

It is a perfect power (a square), and thus also a powerful number.

165279178649025 is a `hidden beast` number, since 1 + 6 + 5 + 27 + 9 + 17 + 86 + 490 + 25 = 666.

165279178649025 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 54831522138561 + 110447656510464 = 7404831^2 + 10509408^2 .

It is a tau number, because it is divible by the number of its divisors (135).

It is not a de Polignac number, because 165279178649025 - 2⁵ = 165279178648993 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 4049649519 + ... + 4049690331.

Almost surely, 2^{165279178649025} is an apocalyptic number.

165279178649025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

165279178649025 is the 12856095-th square number.

165279178649025 is the 6428048-th centered octagonal number.

It is an amenable number.

165279178649025 is an abundant number, since it is smaller than the sum of its proper divisors (190868074748856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165279178649025 is an frugal number, since it uses more digits than its factorization.

165279178649025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81662 (or 40828 counting only the distinct ones).

The product of its (nonzero) digits is 457228800, while the sum is 72.

The spelling of 165279178649025 in words is "one hundred sixty-five trillion, two hundred seventy-nine billion, one hundred seventy-eight million, six hundred forty-nine thousand, twenty-five".