81858613015 has 16 divisors (see below), whose sum is σ = 99102155040. Its totient is φ = 64907251200.

The previous prime is 81858613003. The next prime is 81858613037. The reversal of 81858613015 is 51031685818.

It is not a de Polignac number, because 81858613015 - 2⁷ = 81858612887 is a prime.

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, 319707 + ... + 515683.

It is an arithmetic number, because the mean of its divisors is an integer number (6193884690).

Almost surely, 2^81858613015 is an apocalyptic number.

81858613015 is a deficient number, since it is larger than the sum of its proper divisors (17243542025).

81858613015 is a wasteful number, since it uses less digits than its factorization.

81858613015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196722.

The product of its (nonzero) digits is 230400, while the sum is 46.

The spelling of 81858613015 in words is "eighty-one billion, eight hundred fifty-eight million, six hundred thirteen thousand, fifteen".