85561515081 has 45 divisors (see below), whose sum is σ = 148713755421. Its totient is φ = 48881764008.

The previous prime is 85561515043. The next prime is 85561515101. The reversal of 85561515081 is 18051516558.

The square root of 85561515081 is 292509.

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

85561515081 is a `hidden beast` number, since 8 + 5 + 56 + 1 + 515 + 0 + 81 = 666.

It is not a de Polignac number, because 85561515081 - 2²⁷ = 85427297353 is a prime.

It is a super-2 number, since 2×85561515081² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (85561510081) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 18425746 + ... + 18430388.

Almost surely, 2^85561515081 is an apocalyptic number.

85561515081 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

85561515081 is the 292509-th square number.

85561515081 is the 146255-th centered octagonal number.

It is an amenable number.

85561515081 is a deficient number, since it is larger than the sum of its proper divisors (63152240340).

85561515081 is an frugal number, since it uses more digits than its factorization.

85561515081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9312 (or 4653 counting only the distinct ones).

The product of its (nonzero) digits is 240000, while the sum is 45.

The spelling of 85561515081 in words is "eighty-five billion, five hundred sixty-one million, five hundred fifteen thousand, eighty-one".