21364420 has 48 divisors (see below), whose sum is σ = 55939968. Its totient is φ = 6658560.

The previous prime is 21364411. The next prime is 21364423. The reversal of 21364420 is 2446312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 21364391 and 21364400.

It is not an unprimeable number, because it can be changed into a prime (21364423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5397 + ... + 8476.

It is an arithmetic number, because the mean of its divisors is an integer number (1165416).

Almost surely, 2^21364420 is an apocalyptic number.

21364420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21364420 is an abundant number, since it is smaller than the sum of its proper divisors (34575548).

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

21364420 is a wasteful number, since it uses less digits than its factorization.

21364420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13900 (or 13898 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 21364420 is about 4622.1661588480. The cubic root of 21364420 is about 277.4791586761.

It can be divided in two parts, 2136 and 4420, that added together give a palindrome (6556).

The spelling of 21364420 in words is "twenty-one million, three hundred sixty-four thousand, four hundred twenty".