81358028 has 24 divisors (see below), whose sum is σ = 144080832. Its totient is φ = 40195584.

The previous prime is 81358001. The next prime is 81358087. The reversal of 81358028 is 82085318.

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, 221501 + ... + 221867.

It is an arithmetic number, because the mean of its divisors is an integer number (6003368).

Almost surely, 2^81358028 is an apocalyptic number.

It is an amenable number.

81358028 is a deficient number, since it is larger than the sum of its proper divisors (62722804).

81358028 is a wasteful number, since it uses less digits than its factorization.

81358028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 881 (or 879 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 35.

The square root of 81358028 is about 9019.8685134541. The cubic root of 81358028 is about 433.3114226923.

The spelling of 81358028 in words is "eighty-one million, three hundred fifty-eight thousand, twenty-eight".