15661394 has 16 divisors (see below), whose sum is σ = 27355968. Its totient is φ = 6585072.

The previous prime is 15661391. The next prime is 15661423. The reversal of 15661394 is 49316651.

It is not an unprimeable number, because it can be changed into a prime (15661391) 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, 9812 + ... + 11295.

It is an arithmetic number, because the mean of its divisors is an integer number (1709748).

Almost surely, 2^15661394 is an apocalyptic number.

15661394 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

15661394 is a deficient number, since it is larger than the sum of its proper divisors (11694574).

15661394 is a wasteful number, since it uses less digits than its factorization.

15661394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21169.

The product of its digits is 19440, while the sum is 35.

The square root of 15661394 is about 3957.4479150079. The cubic root of 15661394 is about 250.1939508267.

The spelling of 15661394 in words is "fifteen million, six hundred sixty-one thousand, three hundred ninety-four".