21265850 has 12 divisors (see below), whose sum is σ = 39554574. Its totient is φ = 8506320.

The previous prime is 21265847. The next prime is 21265859. The reversal of 21265850 is 5856212.

It can be written as a sum of positive squares in 3 ways, for example, as 16008001 + 5257849 = 4001^2 + 2293^2 .

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21265859) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 212609 + ... + 212708.

Almost surely, 2^21265850 is an apocalyptic number.

21265850 is a deficient number, since it is larger than the sum of its proper divisors (18288724).

21265850 is a wasteful number, since it uses less digits than its factorization.

21265850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425329 (or 425324 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 21265850 is about 4611.4910820688. The cubic root of 21265850 is about 277.0517612785.

The spelling of 21265850 in words is "twenty-one million, two hundred sixty-five thousand, eight hundred fifty".