81989952 has 56 divisors (see below), whose sum is σ = 236658912. Its totient is φ = 24844800.

The previous prime is 81989933. The next prime is 81989981. The reversal of 81989952 is 25998918.

It is a junction number, because it is equal to n+sod(n) for n = 81989895 and 81989904.

It is a congruent number.

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, 17299 + ... + 21522.

It is an arithmetic number, because the mean of its divisors is an integer number (4226052).

Almost surely, 2^81989952 is an apocalyptic number.

It is an amenable number.

81989952 is an abundant number, since it is smaller than the sum of its proper divisors (154668960).

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

81989952 is a wasteful number, since it uses less digits than its factorization.

81989952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38847 (or 38837 counting only the distinct ones).

The product of its digits is 466560, while the sum is 51.

The square root of 81989952 is about 9054.8303131533. The cubic root of 81989952 is about 434.4304025878.

The spelling of 81989952 in words is "eighty-one million, nine hundred eighty-nine thousand, nine hundred fifty-two".