81037930 has 16 divisors (see below), whose sum is σ = 146140200. Its totient is φ = 32354752.

The previous prime is 81037897. The next prime is 81037981. The reversal of 81037930 is 3973018.

It can be written as a sum of positive squares in 4 ways, for example, as 60886809 + 20151121 = 7803^2 + 4489^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81037892 and 81037901.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1705 + ... + 12844.

Almost surely, 2^81037930 is an apocalyptic number.

81037930 is a deficient number, since it is larger than the sum of its proper divisors (65102270).

81037930 is a wasteful number, since it uses less digits than its factorization.

81037930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15113.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 81037930 is about 9002.1069755919. The cubic root of 81037930 is about 432.7423970053.

The spelling of 81037930 in words is "eighty-one million, thirty-seven thousand, nine hundred thirty".