21273900 has 36 divisors (see below), whose sum is σ = 61553352. Its totient is φ = 5672960.

The previous prime is 21273899. The next prime is 21273911. The reversal of 21273900 is 937212.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 35157 + ... + 35756.

Almost surely, 2^21273900 is an apocalyptic number.

21273900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21273900 is an abundant number, since it is smaller than the sum of its proper divisors (40279452).

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

21273900 is a wasteful number, since it uses less digits than its factorization.

21273900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70930 (or 70923 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 24.

The square root of 21273900 is about 4612.3638191279. The cubic root of 21273900 is about 277.0867153688.

The spelling of 21273900 in words is "twenty-one million, two hundred seventy-three thousand, nine hundred".