15981228 has 36 divisors (see below), whose sum is σ = 42155568. Its totient is φ = 5095200.

The previous prime is 15981211. The next prime is 15981239. The reversal of 15981228 is 82218951.

It is a tau number, because it is divible by the number of its divisors (36).

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 = 15981192 and 15981201.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8823 + ... + 10478.

It is an arithmetic number, because the mean of its divisors is an integer number (1170988).

Almost surely, 2^15981228 is an apocalyptic number.

15981228 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

15981228 is an abundant number, since it is smaller than the sum of its proper divisors (26174340).

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

15981228 is a wasteful number, since it uses less digits than its factorization.

15981228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19334 (or 19329 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 15981228 is about 3997.6528113382. The cubic root of 15981228 is about 251.8856245890.

The spelling of 15981228 in words is "fifteen million, nine hundred eighty-one thousand, two hundred twenty-eight".