21660192 has 36 divisors (see below), whose sum is σ = 61596990. Its totient is φ = 7219968.

The previous prime is 21660173. The next prime is 21660211. The reversal of 21660192 is 29106612.

It is an interprime number because it is at equal distance from previous prime (21660173) and next prime (21660211).

It can be written as a sum of positive squares in only one way, i.e., 13571856 + 8088336 = 3684^2 + 2844^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37317 + ... + 37892.

Almost surely, 2^21660192 is an apocalyptic number.

It is an amenable number.

21660192 is an abundant number, since it is smaller than the sum of its proper divisors (39936798).

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

21660192 is a wasteful number, since it uses less digits than its factorization.

21660192 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75225 (or 75214 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 21660192 is about 4654.0511385244. The cubic root of 21660192 is about 278.7537813104.

The spelling of 21660192 in words is "twenty-one million, six hundred sixty thousand, one hundred ninety-two".