15691428 has 48 divisors (see below), whose sum is σ = 42456960. Its totient is φ = 5002272.

The previous prime is 15691427. The next prime is 15691439. The reversal of 15691428 is 82419651.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 15691392 and 15691401.

It is not an unprimeable number, because it can be changed into a prime (15691427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 675 + ... + 5642.

It is an arithmetic number, because the mean of its divisors is an integer number (884520).

Almost surely, 2^15691428 is an apocalyptic number.

15691428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15691428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21228480).

15691428 is an abundant number, since it is smaller than the sum of its proper divisors (26765532).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15691428 is a wasteful number, since it uses less digits than its factorization.

15691428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6353 (or 6345 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 15691428 is about 3961.2407147256. The cubic root of 15691428 is about 250.3537817843.

The spelling of 15691428 in words is "fifteen million, six hundred ninety-one thousand, four hundred twenty-eight".