81492400 has 60 divisors (see below), whose sum is σ = 213595704. Its totient is φ = 29632000.

The previous prime is 81492361. The next prime is 81492409. The reversal of 81492400 is 429418.

It is a super-2 number, since 2×81492400² = 13282022515520000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81492409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4861 + ... + 13660.

Almost surely, 2^81492400 is an apocalyptic number.

81492400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81492400 is an abundant number, since it is smaller than the sum of its proper divisors (132103304).

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

81492400 is a wasteful number, since it uses less digits than its factorization.

81492400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18550 (or 18539 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 81492400 is about 9027.3141077510. The cubic root of 81492400 is about 433.5498457805.

The spelling of 81492400 in words is "eighty-one million, four hundred ninety-two thousand, four hundred".