15661200 has 120 divisors (see below), whose sum is σ = 51909376. Its totient is φ = 4032000.

The previous prime is 15661193. The next prime is 15661213. The reversal of 15661200 is 216651.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 36990 + ... + 37410.

Almost surely, 2^15661200 is an apocalyptic number.

15661200 is a gapful number since it is divisible by the number (10) 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 15661200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25954688).

15661200 is an abundant number, since it is smaller than the sum of its proper divisors (36248176).

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

15661200 is a wasteful number, since it uses less digits than its factorization.

15661200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473 (or 462 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 15661200 is about 3957.4234041861. The cubic root of 15661200 is about 250.1929177593.

Adding to 15661200 its reverse (216651), we get a palindrome (15877851).

The spelling of 15661200 in words is "fifteen million, six hundred sixty-one thousand, two hundred".