21368418 has 32 divisors (see below), whose sum is σ = 44487360. Its totient is φ = 6834240.

The previous prime is 21368401. The next prime is 21368429. The reversal of 21368418 is 81486312.

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, 39228 + ... + 39768.

It is an arithmetic number, because the mean of its divisors is an integer number (1390230).

Almost surely, 2^21368418 is an apocalyptic number.

21368418 is an abundant number, since it is smaller than the sum of its proper divisors (23118942).

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

21368418 is a wasteful number, since it uses less digits than its factorization.

21368418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 802.

The product of its digits is 9216, while the sum is 33.

The square root of 21368418 is about 4622.5986198241. The cubic root of 21368418 is about 277.4964661509.

The spelling of 21368418 in words is "twenty-one million, three hundred sixty-eight thousand, four hundred eighteen".