81925128 has 32 divisors (see below), whose sum is σ = 227570400. Its totient is φ = 27308304.

The previous prime is 81925111. The next prime is 81925139. The reversal of 81925128 is 82152918.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 81925092 and 81925101.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 189426 + ... + 189857.

It is an arithmetic number, because the mean of its divisors is an integer number (7111575).

Almost surely, 2^81925128 is an apocalyptic number.

It is an amenable number.

81925128 is an abundant number, since it is smaller than the sum of its proper divisors (145645272).

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

81925128 is a wasteful number, since it uses less digits than its factorization.

81925128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379298 (or 379288 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 81925128 is about 9051.2500794089. The cubic root of 81925128 is about 434.3158806624.

The spelling of 81925128 in words is "eighty-one million, nine hundred twenty-five thousand, one hundred twenty-eight".