21356662 has 4 divisors (see below), whose sum is σ = 32034996. Its totient is φ = 10678330.

The previous prime is 21356653. The next prime is 21356689. The reversal of 21356662 is 26665312.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×21356662² = 912214023564488, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5339164 + ... + 5339167.

It is an arithmetic number, because the mean of its divisors is an integer number (8008749).

Almost surely, 2^21356662 is an apocalyptic number.

21356662 is a deficient number, since it is larger than the sum of its proper divisors (10678334).

21356662 is a wasteful number, since it uses less digits than its factorization.

21356662 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10678333.

The product of its digits is 12960, while the sum is 31.

The square root of 21356662 is about 4621.3268657389. The cubic root of 21356662 is about 277.4455678753.

The spelling of 21356662 in words is "twenty-one million, three hundred fifty-six thousand, six hundred sixty-two".