15856401 has 16 divisors (see below), whose sum is σ = 23444928. Its totient is φ = 9451200.

The previous prime is 15856397. The next prime is 15856409. The reversal of 15856401 is 10465851.

It is not a de Polignac number, because 15856401 - 2² = 15856397 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15856409) 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 15 ways as a sum of consecutive naturals, for example, 1926 + ... + 5951.

It is an arithmetic number, because the mean of its divisors is an integer number (1465308).

Almost surely, 2^15856401 is an apocalyptic number.

15856401 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

15856401 is a deficient number, since it is larger than the sum of its proper divisors (7588527).

15856401 is a wasteful number, since it uses less digits than its factorization.

15856401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7952.

The product of its (nonzero) digits is 4800, while the sum is 30.

The square root of 15856401 is about 3982.0096684965. The cubic root of 15856401 is about 251.2280959098.

The spelling of 15856401 in words is "fifteen million, eight hundred fifty-six thousand, four hundred one".