81355400 has 48 divisors (see below), whose sum is σ = 216176640. Its totient is φ = 27892800.

The previous prime is 81355381. The next prime is 81355453. The reversal of 81355400 is 455318.

It is a super-2 number, since 2×81355400² = 13237402218320000, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81355400.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27656 + ... + 30455.

It is an arithmetic number, because the mean of its divisors is an integer number (4503680).

Almost surely, 2^81355400 is an apocalyptic number.

It is an amenable number.

81355400 is an abundant number, since it is smaller than the sum of its proper divisors (134821240).

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

81355400 is a wasteful number, since it uses less digits than its factorization.

81355400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58134 (or 58125 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 81355400 is about 9019.7228338791. The cubic root of 81355400 is about 433.3067570815.

The spelling of 81355400 in words is "eighty-one million, three hundred fifty-five thousand, four hundred".