81925744 has 10 divisors (see below), whose sum is σ = 158731160. Its totient is φ = 40962864.

The previous prime is 81925729. The next prime is 81925751. The reversal of 81925744 is 44752918.

It is a junction number, because it is equal to n+sod(n) for n = 81925697 and 81925706.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 2560164 + ... + 2560195.

It is an arithmetic number, because the mean of its divisors is an integer number (15873116).

Almost surely, 2^81925744 is an apocalyptic number.

It is an amenable number.

81925744 is a deficient number, since it is larger than the sum of its proper divisors (76805416).

81925744 is a wasteful number, since it uses less digits than its factorization.

81925744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5120367 (or 5120361 counting only the distinct ones).

The product of its digits is 80640, while the sum is 40.

The square root of 81925744 is about 9051.2841077938. The cubic root of 81925744 is about 434.3169692088.

The spelling of 81925744 in words is "eighty-one million, nine hundred twenty-five thousand, seven hundred forty-four".