81535756404 has 24 divisors (see below), whose sum is σ = 195391993888. Its totient is φ = 26444028960.

The previous prime is 81535756399. The next prime is 81535756409. The reversal of 81535756404 is 40465753518.

It is an interprime number because it is at equal distance from previous prime (81535756399) and next prime (81535756409).

It is a super-2 number, since 2×81535756404² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81535756409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91819102 + ... + 91819989.

Almost surely, 2^81535756404 is an apocalyptic number.

It is an amenable number.

81535756404 is an abundant number, since it is smaller than the sum of its proper divisors (113856237484).

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

81535756404 is a wasteful number, since it uses less digits than its factorization.

81535756404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183639135 (or 183639133 counting only the distinct ones).

The product of its (nonzero) digits is 2016000, while the sum is 48.

The spelling of 81535756404 in words is "eighty-one billion, five hundred thirty-five million, seven hundred fifty-six thousand, four hundred four".