21357394 has 8 divisors (see below), whose sum is σ = 32422320. Its totient is φ = 10549956.

The previous prime is 21357377. The next prime is 21357397. The reversal of 21357394 is 49375312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21357394² = 912276556942472, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21357397) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64164 + ... + 64495.

It is an arithmetic number, because the mean of its divisors is an integer number (4052790).

Almost surely, 2^21357394 is an apocalyptic number.

21357394 is a deficient number, since it is larger than the sum of its proper divisors (11064926).

21357394 is a wasteful number, since it uses less digits than its factorization.

21357394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128744.

The product of its digits is 22680, while the sum is 34.

The square root of 21357394 is about 4621.4060630938. The cubic root of 21357394 is about 277.4487376564.

The spelling of 21357394 in words is "twenty-one million, three hundred fifty-seven thousand, three hundred ninety-four".