81487992 has 32 divisors (see below), whose sum is σ = 208691280. Its totient is φ = 26499840.

The previous prime is 81487969. The next prime is 81487993. The reversal of 81487992 is 29978418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81487993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40423 + ... + 42390.

Almost surely, 2^81487992 is an apocalyptic number.

81487992 is a gapful number since it is divisible by the number (82) formed by its first and last digit.

It is an amenable number.

81487992 is an abundant number, since it is smaller than the sum of its proper divisors (127203288).

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

81487992 is a wasteful number, since it uses less digits than its factorization.

81487992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82863 (or 82859 counting only the distinct ones).

The product of its digits is 290304, while the sum is 48.

The square root of 81487992 is about 9027.0699565252. The cubic root of 81487992 is about 433.5420286009.

The spelling of 81487992 in words is "eighty-one million, four hundred eighty-seven thousand, nine hundred ninety-two".