81558675 has 72 divisors (see below), whose sum is σ = 164656128. Its totient is φ = 38232000.

The previous prime is 81558661. The next prime is 81558689. The reversal of 81558675 is 57685518.

It is an interprime number because it is at equal distance from previous prime (81558661) and next prime (81558689).

It is not a de Polignac number, because 81558675 - 2¹⁵ = 81525907 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 81558675.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 76194 + ... + 77256.

Almost surely, 2^81558675 is an apocalyptic number.

81558675 is an abundant number, since it is smaller than the sum of its proper divisors (83097453).

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

81558675 is a wasteful number, since it uses less digits than its factorization.

81558675 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1121 (or 1113 counting only the distinct ones).

The product of its digits is 336000, while the sum is 45.

The square root of 81558675 is about 9030.9841656378. The cubic root of 81558675 is about 433.6673443865.

The spelling of 81558675 in words is "eighty-one million, five hundred fifty-eight thousand, six hundred seventy-five".