81393058 has 4 divisors (see below), whose sum is σ = 122089590. Its totient is φ = 40696528.

The previous prime is 81393047. The next prime is 81393061. The reversal of 81393058 is 85039318.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 68840209 + 12552849 = 8297^2 + 3543^2 .

It is a super-3 number, since 3×81393058³ (a number of 25 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20348263 + ... + 20348266.

Almost surely, 2^81393058 is an apocalyptic number.

81393058 is a deficient number, since it is larger than the sum of its proper divisors (40696532).

81393058 is a wasteful number, since it uses less digits than its factorization.

81393058 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40696531.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 81393058 is about 9021.8101287934. The cubic root of 81393058 is about 433.3736034896.

The spelling of 81393058 in words is "eighty-one million, three hundred ninety-three thousand, fifty-eight".