163990434515625 has 105 divisors (see below), whose sum is σ = 306239690101323. Its totient is φ = 87453881550000.

The previous prime is 163990434515591. The next prime is 163990434515627. The reversal of 163990434515625 is 526515434099361.

It is a happy number.

The square root of 163990434515625 is 12805875.

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

163990434515625 is a `hidden beast` number, since 1 + 6 + 3 + 9 + 90 + 4 + 3 + 4 + 515 + 6 + 25 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 143671363717401 + 20319070798224 = 11986299^2 + 4507668^2 .

It is a de Polignac number, because none of the positive numbers 2^k-163990434515625 is a prime.

It is a super-2 number, since 2×163990434515625² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (163990434515627) by changing a digit.

It is a polite number, since it can be written in 104 ways as a sum of consecutive naturals, for example, 14406603684 + ... + 14406615066.

Almost surely, 2^{163990434515625} is an apocalyptic number.

163990434515625 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

163990434515625 is the 12805875-th square number.

163990434515625 is the 6402938-th centered octagonal number.

It is an amenable number.

163990434515625 is a deficient number, since it is larger than the sum of its proper divisors (142249255585698).

163990434515625 is an frugal number, since it uses more digits than its factorization.

163990434515625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22808 (or 11391 counting only the distinct ones).

The product of its (nonzero) digits is 104976000, while the sum is 63.

The spelling of 163990434515625 in words is "one hundred sixty-three trillion, nine hundred ninety billion, four hundred thirty-four million, five hundred fifteen thousand, six hundred twenty-five".