81623537013 has 16 divisors (see below), whose sum is σ = 114954684416. Its totient is φ = 51435684720.

The previous prime is 81623536997. The next prime is 81623537041. The reversal of 81623537013 is 31073532618.

It is not a de Polignac number, because 81623537013 - 2⁴ = 81623536997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81623539013) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10201495 + ... + 10209492.

It is an arithmetic number, because the mean of its divisors is an integer number (7184667776).

Almost surely, 2^81623537013 is an apocalyptic number.

It is an amenable number.

81623537013 is a deficient number, since it is larger than the sum of its proper divisors (33331147403).

81623537013 is a wasteful number, since it uses less digits than its factorization.

81623537013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20411064.

The product of its (nonzero) digits is 90720, while the sum is 39.

The spelling of 81623537013 in words is "eighty-one billion, six hundred twenty-three million, five hundred thirty-seven thousand, thirteen".