21701966 has 32 divisors (see below), whose sum is σ = 38556000. Its totient is φ = 9085440.

The previous prime is 21701959. The next prime is 21701987. The reversal of 21701966 is 66910712.

It is a happy number.

It is a congruent number.

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, 48110 + ... + 48558.

It is an arithmetic number, because the mean of its divisors is an integer number (1204875).

Almost surely, 2^21701966 is an apocalyptic number.

21701966 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21701966 is a deficient number, since it is larger than the sum of its proper divisors (16854034).

21701966 is a wasteful number, since it uses less digits than its factorization.

21701966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 501 (or 475 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 21701966 is about 4658.5368947772. The cubic root of 21701966 is about 278.9328684037.

The spelling of 21701966 in words is "twenty-one million, seven hundred one thousand, nine hundred sixty-six".