21900297 has 16 divisors (see below), whose sum is σ = 29752128. Its totient is φ = 14327040.

The previous prime is 21900283. The next prime is 21900299. The reversal of 21900297 is 79200912.

It is not a de Polignac number, because 21900297 - 2¹¹ = 21898249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21900299) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69813 + ... + 70125.

It is an arithmetic number, because the mean of its divisors is an integer number (1859508).

Almost surely, 2^21900297 is an apocalyptic number.

It is an amenable number.

21900297 is a deficient number, since it is larger than the sum of its proper divisors (7851831).

21900297 is a wasteful number, since it uses less digits than its factorization.

21900297 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680.

The product of its (nonzero) digits is 2268, while the sum is 30.

The square root of 21900297 is about 4679.7753151193. The cubic root of 21900297 is about 279.7800015102.

The spelling of 21900297 in words is "twenty-one million, nine hundred thousand, two hundred ninety-seven".