81933537 has 12 divisors (see below), whose sum is σ = 127080816. Its totient is φ = 46819080.

The previous prime is 81933517. The next prime is 81933541. The reversal of 81933537 is 73533918.

It is not a de Polignac number, because 81933537 - 2⁶ = 81933473 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81933495 and 81933504.

It is not an unprimeable number, because it can be changed into a prime (81933517) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 278539 + ... + 278832.

It is an arithmetic number, because the mean of its divisors is an integer number (10590068).

Almost surely, 2^81933537 is an apocalyptic number.

It is an amenable number.

81933537 is a deficient number, since it is larger than the sum of its proper divisors (45147279).

81933537 is a wasteful number, since it uses less digits than its factorization.

81933537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557388 (or 557381 counting only the distinct ones).

The product of its digits is 68040, while the sum is 39.

The square root of 81933537 is about 9051.7145889605. The cubic root of 81933537 is about 434.3307399100.

The spelling of 81933537 in words is "eighty-one million, nine hundred thirty-three thousand, five hundred thirty-seven".