81575400 has 96 divisors (see below), whose sum is σ = 256233600. Its totient is φ = 21465600.

The previous prime is 81575399. The next prime is 81575423. The reversal of 81575400 is 457518.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46540 + ... + 48260.

It is an arithmetic number, because the mean of its divisors is an integer number (2669100).

Almost surely, 2^81575400 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81575400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128116800).

81575400 is an abundant number, since it is smaller than the sum of its proper divisors (174658200).

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

81575400 is a wasteful number, since it uses less digits than its factorization.

81575400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1819 (or 1810 counting only the distinct ones).

The product of its (nonzero) digits is 5600, while the sum is 30.

The square root of 81575400 is about 9031.9100969839. The cubic root of 81575400 is about 433.6969859936.

The spelling of 81575400 in words is "eighty-one million, five hundred seventy-five thousand, four hundred".