15691438 has 16 divisors (see below), whose sum is σ = 27556704. Its totient is φ = 6560640.

The previous prime is 15691427. The next prime is 15691439. The reversal of 15691438 is 83419651.

It is a junction number, because it is equal to n+sod(n) for n = 15691397 and 15691406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15691439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13095 + ... + 14242.

It is an arithmetic number, because the mean of its divisors is an integer number (1722294).

Almost surely, 2^15691438 is an apocalyptic number.

15691438 is a deficient number, since it is larger than the sum of its proper divisors (11865266).

15691438 is a wasteful number, since it uses less digits than its factorization.

15691438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27387.

The product of its digits is 25920, while the sum is 37.

The square root of 15691438 is about 3961.2419769562. The cubic root of 15691438 is about 250.3538349670.

It can be divided in two parts, 15691 and 438, that added together give a square (16129 = 127²).

The spelling of 15691438 in words is "fifteen million, six hundred ninety-one thousand, four hundred thirty-eight".