15661339 has 4 divisors (see below), whose sum is σ = 16485640. Its totient is φ = 14837040.

The previous prime is 15661337. The next prime is 15661343. The reversal of 15661339 is 93316651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93316651 = 83 ⋅1124297.

It is a cyclic number.

It is not a de Polignac number, because 15661339 - 2¹ = 15661337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15661333) 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, 412122 + ... + 412159.

It is an arithmetic number, because the mean of its divisors is an integer number (4121410).

Almost surely, 2^15661339 is an apocalyptic number.

15661339 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

15661339 is a deficient number, since it is larger than the sum of its proper divisors (824301).

15661339 is an equidigital number, since it uses as much as digits as its factorization.

15661339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 824300.

The product of its digits is 14580, while the sum is 34.

The square root of 15661339 is about 3957.4409660790. The cubic root of 15661339 is about 250.1936579477.

The spelling of 15661339 in words is "fifteen million, six hundred sixty-one thousand, three hundred thirty-nine".