21748992 has 36 divisors (see below), whose sum is σ = 57886080. Its totient is φ = 7249408.

The previous prime is 21748981. The next prime is 21748999. The reversal of 21748992 is 29984712.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21748999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13392 + ... + 14927.

Almost surely, 2^21748992 is an apocalyptic number.

It is an amenable number.

21748992 is an abundant number, since it is smaller than the sum of its proper divisors (36137088).

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

21748992 is an equidigital number, since it uses as much as digits as its factorization.

21748992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28338 (or 28324 counting only the distinct ones).

The product of its digits is 72576, while the sum is 42.

The square root of 21748992 is about 4663.5814563488. The cubic root of 21748992 is about 279.1341963076.

The spelling of 21748992 in words is "twenty-one million, seven hundred forty-eight thousand, nine hundred ninety-two".