81261504 has 42 divisors (see below), whose sum is σ = 232923080. Its totient is φ = 27086976.

The previous prime is 81261503. The next prime is 81261511. The reversal of 81261504 is 40516218.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81261503) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 69964 + ... + 71115.

Almost surely, 2^81261504 is an apocalyptic number.

It is an amenable number.

81261504 is an abundant number, since it is smaller than the sum of its proper divisors (151661576).

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

81261504 is a wasteful number, since it uses less digits than its factorization.

81261504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141097 (or 141084 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 81261504 is about 9014.5162931796. The cubic root of 81261504 is about 433.1399931718.

The spelling of 81261504 in words is "eighty-one million, two hundred sixty-one thousand, five hundred four".