81955400 has 24 divisors (see below), whose sum is σ = 190546770. Its totient is φ = 32782080.

The previous prime is 81955361. The next prime is 81955403. The reversal of 81955400 is 455918.

It can be written as a sum of positive squares in 3 ways, for example, as 31516996 + 50438404 = 5614^2 + 7102^2 .

It is not an unprimeable number, because it can be changed into a prime (81955403) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 204689 + ... + 205088.

Almost surely, 2^81955400 is an apocalyptic number.

It is an amenable number.

81955400 is an abundant number, since it is smaller than the sum of its proper divisors (108591370).

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

81955400 is a wasteful number, since it uses less digits than its factorization.

81955400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409793 (or 409784 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 81955400 is about 9052.9221801582. The cubic root of 81955400 is about 434.3693684897.

The spelling of 81955400 in words is "eighty-one million, nine hundred fifty-five thousand, four hundred".