21297850 has 36 divisors (see below), whose sum is σ = 46086894. Its totient is φ = 7301280.

The previous prime is 21297817. The next prime is 21297851. The reversal of 21297850 is 5879212.

It can be written as a sum of positive squares in 3 ways, for example, as 10055241 + 11242609 = 3171^2 + 3353^2 .

It is not an unprimeable number, because it can be changed into a prime (21297851) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1897 + ... + 6796.

Almost surely, 2^21297850 is an apocalyptic number.

21297850 is an abundant number, since it is smaller than the sum of its proper divisors (24789044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21297850 is a wasteful number, since it uses less digits than its factorization.

21297850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8719 (or 8707 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 21297850 is about 4614.9593714355. The cubic root of 21297850 is about 277.1906571010.

The spelling of 21297850 in words is "twenty-one million, two hundred ninety-seven thousand, eight hundred fifty".