21292280 has 16 divisors (see below), whose sum is σ = 47907720. Its totient is φ = 8516896.

The previous prime is 21292277. The next prime is 21292283. The reversal of 21292280 is 8229212.

It is an interprime number because it is at equal distance from previous prime (21292277) and next prime (21292283).

It is a super-2 number, since 2×21292280² = 906722375196800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21292283) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266114 + ... + 266193.

Almost surely, 2^21292280 is an apocalyptic number.

21292280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21292280 is an abundant number, since it is smaller than the sum of its proper divisors (26615440).

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

21292280 is a wasteful number, since it uses less digits than its factorization.

21292280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532318 (or 532314 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 21292280 is about 4614.3558597057. The cubic root of 21292280 is about 277.1664905525.

The spelling of 21292280 in words is "twenty-one million, two hundred ninety-two thousand, two hundred eighty".