15900012 has 18 divisors (see below), whose sum is σ = 40191788. Its totient is φ = 5299992.

The previous prime is 15899999. The next prime is 15900013. The reversal of 15900012 is 21000951.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (15900013) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 220798 + ... + 220869.

Almost surely, 2^15900012 is an apocalyptic number.

15900012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

15900012 is an abundant number, since it is smaller than the sum of its proper divisors (24291776).

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

15900012 is a wasteful number, since it uses less digits than its factorization.

15900012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441677 (or 441672 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 18.

The square root of 15900012 is about 3987.4819121847. The cubic root of 15900012 is about 251.4582086399.

Adding to 15900012 its reverse (21000951), we get a palindrome (36900963).

The spelling of 15900012 in words is "fifteen million, nine hundred thousand, twelve".