81620874 has 24 divisors (see below), whose sum is σ = 179487360. Its totient is φ = 26800488.

The previous prime is 81620857. The next prime is 81620909. The reversal of 81620874 is 47802618.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32634 + ... + 35045.

It is an arithmetic number, because the mean of its divisors is an integer number (7478640).

Almost surely, 2^81620874 is an apocalyptic number.

81620874 is an abundant number, since it is smaller than the sum of its proper divisors (97866486).

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

81620874 is a wasteful number, since it uses less digits than its factorization.

81620874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67754 (or 67751 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 81620874 is about 9034.4271539484. The cubic root of 81620874 is about 433.7775587857. Note that the first 3 decimals are identical.

The spelling of 81620874 in words is "eighty-one million, six hundred twenty thousand, eight hundred seventy-four".