15661971073 has 8 divisors (see below), whose sum is σ = 18841469120. Its totient is φ = 12717991440.

The previous prime is 15661971047. The next prime is 15661971107. The reversal of 15661971073 is 37017916651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 15661971073 - 2²¹ = 15659873921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15661971473) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58879458 + ... + 58879723.

It is an arithmetic number, because the mean of its divisors is an integer number (2355183640).

Almost surely, 2^15661971073 is an apocalyptic number.

It is an amenable number.

15661971073 is a deficient number, since it is larger than the sum of its proper divisors (3179498047).

15661971073 is a wasteful number, since it uses less digits than its factorization.

15661971073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117759207.

The product of its (nonzero) digits is 238140, while the sum is 46.

The spelling of 15661971073 in words is "fifteen billion, six hundred sixty-one million, nine hundred seventy-one thousand, seventy-three".