21364516 has 24 divisors (see below), whose sum is σ = 39259584. Its totient is φ = 10153440.

The previous prime is 21364513. The next prime is 21364517. The reversal of 21364516 is 61546312.

It is not an unprimeable number, because it can be changed into a prime (21364513) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16011 + ... + 17293.

It is an arithmetic number, because the mean of its divisors is an integer number (1635816).

Almost surely, 2^21364516 is an apocalyptic number.

It is an amenable number.

21364516 is a deficient number, since it is larger than the sum of its proper divisors (17895068).

21364516 is a wasteful number, since it uses less digits than its factorization.

21364516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1491 (or 1489 counting only the distinct ones).

The product of its digits is 4320, while the sum is 28.

The square root of 21364516 is about 4622.1765435777. The cubic root of 21364516 is about 277.4795742886.

The spelling of 21364516 in words is "twenty-one million, three hundred sixty-four thousand, five hundred sixteen".