21917950 has 24 divisors (see below), whose sum is σ = 40892472. Its totient is φ = 8740320.

The previous prime is 21917927. The next prime is 21917977. The reversal of 21917950 is 5971912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27457 + ... + 28243.

It is an arithmetic number, because the mean of its divisors is an integer number (1703853).

Almost surely, 2^21917950 is an apocalyptic number.

21917950 is a deficient number, since it is larger than the sum of its proper divisors (18974522).

21917950 is a wasteful number, since it uses less digits than its factorization.

21917950 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1356 (or 1351 counting only the distinct ones).

The product of its (nonzero) digits is 5670, while the sum is 34.

The square root of 21917950 is about 4681.6610300192. The cubic root of 21917950 is about 279.8551546756.

The spelling of 21917950 in words is "twenty-one million, nine hundred seventeen thousand, nine hundred fifty".