81558074 has 8 divisors (see below), whose sum is σ = 131747700. Its totient is φ = 37642176.

The previous prime is 81558073. The next prime is 81558079. The reversal of 81558074 is 47085518.

It can be written as a sum of positive squares in 2 ways, for example, as 80013025 + 1545049 = 8945^2 + 1243^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (81558073) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1568399 + ... + 1568450.

Almost surely, 2^81558074 is an apocalyptic number.

81558074 is a deficient number, since it is larger than the sum of its proper divisors (50189626).

81558074 is a wasteful number, since it uses less digits than its factorization.

81558074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3136864.

The product of its (nonzero) digits is 44800, while the sum is 38.

The square root of 81558074 is about 9030.9508912406. The cubic root of 81558074 is about 433.6662791628. Note that the first 3 decimals are identical.

The spelling of 81558074 in words is "eighty-one million, five hundred fifty-eight thousand, seventy-four".