21364140 has 48 divisors (see below), whose sum is σ = 68366592. Its totient is φ = 4883136.

The previous prime is 21364139. The next prime is 21364169. The reversal of 21364140 is 4146312.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25014 + ... + 25853.

It is an arithmetic number, because the mean of its divisors is an integer number (1424304).

Almost surely, 2^21364140 is an apocalyptic number.

21364140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21364140 is an abundant number, since it is smaller than the sum of its proper divisors (47002452).

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

21364140 is a wasteful number, since it uses less digits than its factorization.

21364140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50886 (or 50884 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 21364140 is about 4622.1358699199. The cubic root of 21364140 is about 277.4779464659.

The spelling of 21364140 in words is "twenty-one million, three hundred sixty-four thousand, one hundred forty".