81538148448758 has 32 divisors (see below), whose sum is σ = 125016013799424. Its totient is φ = 39867629229792.

The previous prime is 81538148448749. The next prime is 81538148448781. The reversal of 81538148448758 is 85784484183518.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1561319435 + ... + 1561371657.

It is an arithmetic number, because the mean of its divisors is an integer number (3906750431232).

Almost surely, 2^{81538148448758} is an apocalyptic number.

81538148448758 is a deficient number, since it is larger than the sum of its proper divisors (43477865350666).

81538148448758 is a wasteful number, since it uses less digits than its factorization.

81538148448758 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66116.

The product of its digits is 1101004800, while the sum is 74.

The spelling of 81538148448758 in words is "eighty-one trillion, five hundred thirty-eight billion, one hundred forty-eight million, four hundred forty-eight thousand, seven hundred fifty-eight".