15681228406866 has 192 divisors, whose sum is σ = 37562653739520. Its totient is φ = 4688564705280.

The previous prime is 15681228406829. The next prime is 15681228406889. The reversal of 15681228406866 is 66860482218651.

15681228406866 is a `hidden beast` number, since 1 + 56 + 81 + 2 + 28 + 406 + 86 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3155809230 + ... + 3155814198.

It is an arithmetic number, because the mean of its divisors is an integer number (195638821560).

Almost surely, 2^{15681228406866} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15681228406866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18781326869760).

15681228406866 is an abundant number, since it is smaller than the sum of its proper divisors (21881425332654).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15681228406866 is a wasteful number, since it uses less digits than its factorization.

15681228406866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5809 (or 5806 counting only the distinct ones).

The product of its (nonzero) digits is 53084160, while the sum is 63.

The spelling of 15681228406866 in words is "fifteen trillion, six hundred eighty-one billion, two hundred twenty-eight million, four hundred six thousand, eight hundred sixty-six".