15681228406865 has 16 divisors (see below), whose sum is σ = 21589364391552. Its totient is φ = 10711002476544.

The previous prime is 15681228406829. The next prime is 15681228406889. The reversal of 15681228406865 is 56860482218651.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15681228406865 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15681228406798 and 15681228406807.

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, 871654619 + ... + 871672608.

It is an arithmetic number, because the mean of its divisors is an integer number (1349335274472).

Almost surely, 2^{15681228406865} is an apocalyptic number.

It is an amenable number.

15681228406865 is a deficient number, since it is larger than the sum of its proper divisors (5908135984687).

15681228406865 is a wasteful number, since it uses less digits than its factorization.

15681228406865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1743327496.

The product of its (nonzero) digits is 44236800, while the sum is 62.

The spelling of 15681228406865 in words is "fifteen trillion, six hundred eighty-one billion, two hundred twenty-eight million, four hundred six thousand, eight hundred sixty-five".