81624470 has 32 divisors (see below), whose sum is σ = 153888768. Its totient is φ = 31112928.

The previous prime is 81624461. The next prime is 81624509. The reversal of 81624470 is 7442618.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83927 + ... + 84893.

It is an arithmetic number, because the mean of its divisors is an integer number (4809024).

Almost surely, 2^81624470 is an apocalyptic number.

81624470 is a deficient number, since it is larger than the sum of its proper divisors (72264298).

81624470 is a wasteful number, since it uses less digits than its factorization.

81624470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1364.

The product of its (nonzero) digits is 10752, while the sum is 32.

The square root of 81624470 is about 9034.6261682485. The cubic root of 81624470 is about 433.7839290564.

The spelling of 81624470 in words is "eighty-one million, six hundred twenty-four thousand, four hundred seventy".