15515961 has 8 divisors (see below), whose sum is σ = 21587520. Its totient is φ = 9894192.

The previous prime is 15515959. The next prime is 15516001. The reversal of 15515961 is 16951551.

15515961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 15515961 - 2¹ = 15515959 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15515911) 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, 112366 + ... + 112503.

It is an arithmetic number, because the mean of its divisors is an integer number (2698440).

Almost surely, 2^15515961 is an apocalyptic number.

It is an amenable number.

15515961 is a deficient number, since it is larger than the sum of its proper divisors (6071559).

15515961 is a wasteful number, since it uses less digits than its factorization.

15515961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224895.

The product of its digits is 6750, while the sum is 33.

The square root of 15515961 is about 3939.0304644671. The cubic root of 15515961 is about 249.4171006363.

The spelling of 15515961 in words is "fifteen million, five hundred fifteen thousand, nine hundred sixty-one".