15961613 has 4 divisors (see below), whose sum is σ = 15990528. Its totient is φ = 15932700.

The previous prime is 15961597. The next prime is 15961619. The reversal of 15961613 is 31616951.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 15961613 - 2⁴ = 15961597 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15961613.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15961619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13613 + ... + 14738.

It is an arithmetic number, because the mean of its divisors is an integer number (3997632).

Almost surely, 2^15961613 is an apocalyptic number.

It is an amenable number.

15961613 is a deficient number, since it is larger than the sum of its proper divisors (28915).

15961613 is an equidigital number, since it uses as much as digits as its factorization.

15961613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28914.

The product of its digits is 4860, while the sum is 32.

The square root of 15961613 is about 3995.1987434920. The cubic root of 15961613 is about 251.7825294808.

The spelling of 15961613 in words is "fifteen million, nine hundred sixty-one thousand, six hundred thirteen".