21273020 has 36 divisors (see below), whose sum is σ = 45526152. Its totient is φ = 8349600.

The previous prime is 21273019. The next prime is 21273023. The reversal of 21273020 is 2037212.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 21273020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21273023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 100715 + ... + 100925.

Almost surely, 2^21273020 is an apocalyptic number.

21273020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21273020 is an abundant number, since it is smaller than the sum of its proper divisors (24253132).

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

21273020 is a wasteful number, since it uses less digits than its factorization.

21273020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 17.

The square root of 21273020 is about 4612.2684223709. The cubic root of 21273020 is about 277.0828947299.

The spelling of 21273020 in words is "twenty-one million, two hundred seventy-three thousand, twenty".