81620976 has 20 divisors (see below), whose sum is σ = 210854312. Its totient is φ = 27206976.

The previous prime is 81620969. The next prime is 81620977. The reversal of 81620976 is 67902618.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81620977) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 850171 + ... + 850266.

Almost surely, 2^81620976 is an apocalyptic number.

It is an amenable number.

81620976 is an abundant number, since it is smaller than the sum of its proper divisors (129233336).

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

81620976 is a wasteful number, since it uses less digits than its factorization.

81620976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1700448 (or 1700442 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 81620976 is about 9034.4327990195. The cubic root of 81620976 is about 433.7777394801. Note that the first 4 decimals are identical.

The spelling of 81620976 in words is "eighty-one million, six hundred twenty thousand, nine hundred seventy-six".