21359420 has 24 divisors (see below), whose sum is σ = 47216400. Its totient is φ = 8093952.

The previous prime is 21359417. The next prime is 21359431. The reversal of 21359420 is 2495312.

It is a self number, because there is not a number n which added to its sum of digits gives 21359420.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27725 + ... + 28484.

It is an arithmetic number, because the mean of its divisors is an integer number (1967350).

Almost surely, 2^21359420 is an apocalyptic number.

21359420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21359420 is an abundant number, since it is smaller than the sum of its proper divisors (25856980).

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

21359420 is a wasteful number, since it uses less digits than its factorization.

21359420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56237 (or 56235 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 21359420 is about 4621.6252552538. The cubic root of 21359420 is about 277.4575104710.

The spelling of 21359420 in words is "twenty-one million, three hundred fifty-nine thousand, four hundred twenty".