15944121 has 20 divisors (see below), whose sum is σ = 24403764. Its totient is φ = 10368000.

The previous prime is 15944111. The next prime is 15944143. The reversal of 15944121 is 12144951.

It can be written as a sum of positive squares in 2 ways, for example, as 4247721 + 11696400 = 2061^2 + 3420^2 .

It is not a de Polignac number, because 15944121 - 2¹⁵ = 15911353 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (15944111) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 921 + ... + 5721.

Almost surely, 2^15944121 is an apocalyptic number.

It is an amenable number.

15944121 is a deficient number, since it is larger than the sum of its proper divisors (8459643).

15944121 is an equidigital number, since it uses as much as digits as its factorization.

15944121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4854 (or 4845 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 15944121 is about 3993.0090157674. The cubic root of 15944121 is about 251.6905214488.

The spelling of 15944121 in words is "fifteen million, nine hundred forty-four thousand, one hundred twenty-one".