15961949 has 4 divisors (see below), whose sum is σ = 15991164. Its totient is φ = 15932736.

The previous prime is 15961943. The next prime is 15961951. The reversal of 15961949 is 94916951.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2220100 + 13741849 = 1490^2 + 3707^2 .

It is a cyclic number.

It is not a de Polignac number, because 15961949 - 2²⁰ = 14913373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15961943) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13772 + ... + 14885.

It is an arithmetic number, because the mean of its divisors is an integer number (3997791).

Almost surely, 2^15961949 is an apocalyptic number.

It is an amenable number.

15961949 is a deficient number, since it is larger than the sum of its proper divisors (29215).

15961949 is an equidigital number, since it uses as much as digits as its factorization.

15961949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29214.

The product of its digits is 87480, while the sum is 44.

The square root of 15961949 is about 3995.2407937445. The cubic root of 15961949 is about 251.7842961848.

The spelling of 15961949 in words is "fifteen million, nine hundred sixty-one thousand, nine hundred forty-nine".