21649892 has 72 divisors (see below), whose sum is σ = 46085760. Its totient is φ = 8809920.

The previous prime is 21649883. The next prime is 21649909. The reversal of 21649892 is 29894612.

It is a super-2 number, since 2×21649892² = 937435647223328, which contains 22 as substring.

Its product of digits (62208) is a multiple of the sum of its prime divisors (108).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 460613 + ... + 460659.

It is an arithmetic number, because the mean of its divisors is an integer number (640080).

Almost surely, 2^21649892 is an apocalyptic number.

21649892 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21649892 is an abundant number, since it is smaller than the sum of its proper divisors (24435868).

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

21649892 is a wasteful number, since it uses less digits than its factorization.

21649892 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129 (or 108 counting only the distinct ones).

The product of its digits is 62208, while the sum is 41.

The square root of 21649892 is about 4652.9444441128. The cubic root of 21649892 is about 278.7095893479.

The spelling of 21649892 in words is "twenty-one million, six hundred forty-nine thousand, eight hundred ninety-two".