81913370 has 96 divisors (see below), whose sum is σ = 195350400. Its totient is φ = 24140160.

The previous prime is 81913343. The next prime is 81913379. The reversal of 81913370 is 7331918.

It is not an unprimeable number, because it can be changed into a prime (81913379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 160676 + ... + 161184.

It is an arithmetic number, because the mean of its divisors is an integer number (2034900).

Almost surely, 2^81913370 is an apocalyptic number.

81913370 is an abundant number, since it is smaller than the sum of its proper divisors (113437030).

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

81913370 is a wasteful number, since it uses less digits than its factorization.

81913370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 564 (or 553 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 81913370 is about 9050.6005325614. The cubic root of 81913370 is about 434.2951018099.

The spelling of 81913370 in words is "eighty-one million, nine hundred thirteen thousand, three hundred seventy".