81156900069 has 24 divisors (see below), whose sum is σ = 133996916352. Its totient is φ = 46367195040.

The previous prime is 81156900053. The next prime is 81156900133. The reversal of 81156900069 is 96000965118.

81156900069 is a `hidden beast` number, since 81 + 1 + 569 + 0 + 0 + 0 + 6 + 9 = 666.

It is not a de Polignac number, because 81156900069 - 2⁴ = 81156900053 is a prime.

It is a super-2 number, since 2×81156900069² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81156899997 and 81156900033.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81156900169) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 256072 + ... + 477374.

It is an arithmetic number, because the mean of its divisors is an integer number (5583204848).

Almost surely, 2^81156900069 is an apocalyptic number.

It is an amenable number.

81156900069 is a deficient number, since it is larger than the sum of its proper divisors (52840016283).

81156900069 is a wasteful number, since it uses less digits than its factorization.

81156900069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227137 (or 227134 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The spelling of 81156900069 in words is "eighty-one billion, one hundred fifty-six million, nine hundred thousand, sixty-nine".