81430858 has 12 divisors (see below), whose sum is σ = 125540982. Its totient is φ = 39613680.

The previous prime is 81430847. The next prime is 81430883. The reversal of 81430858 is 85803418.

It can be written as a sum of positive squares in 3 ways, for example, as 74943649 + 6487209 = 8657^2 + 2547^2 .

It is a Harshad number since it is a multiple of its sum of digits (37).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12133 + ... + 17608.

Almost surely, 2^81430858 is an apocalyptic number.

81430858 is a deficient number, since it is larger than the sum of its proper divisors (44110124).

81430858 is a wasteful number, since it uses less digits than its factorization.

81430858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29817 (or 29780 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 37.

The square root of 81430858 is about 9023.9048088951. The cubic root of 81430858 is about 433.4406812287.

The spelling of 81430858 in words is "eighty-one million, four hundred thirty thousand, eight hundred fifty-eight".