21420364 has 24 divisors (see below), whose sum is σ = 43839488. Its totient is φ = 8966160.

The previous prime is 21420331. The next prime is 21420397. The reversal of 21420364 is 46302412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21420331) and next prime (21420397).

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, 7692 + ... + 10099.

Almost surely, 2^21420364 is an apocalyptic number.

It is an amenable number.

21420364 is an abundant number, since it is smaller than the sum of its proper divisors (22419124).

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

21420364 is a wasteful number, since it uses less digits than its factorization.

21420364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17845 (or 17843 counting only the distinct ones).

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

The square root of 21420364 is about 4628.2139103546. The cubic root of 21420364 is about 277.7211461202.

Adding to 21420364 its reverse (46302412), we get a palindrome (67722776).

The spelling of 21420364 in words is "twenty-one million, four hundred twenty thousand, three hundred sixty-four".