21250899 has 6 divisors (see below), whose sum is σ = 30695756. Its totient is φ = 14167260.

The previous prime is 21250877. The next prime is 21250961. The reversal of 21250899 is 99805212.

It is not a de Polignac number, because 21250899 - 2⁷ = 21250771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21250819) 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, 1180597 + ... + 1180614.

Almost surely, 2^21250899 is an apocalyptic number.

21250899 is a deficient number, since it is larger than the sum of its proper divisors (9444857).

21250899 is a wasteful number, since it uses less digits than its factorization.

21250899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2361217 (or 2361214 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 21250899 is about 4609.8697378559. The cubic root of 21250899 is about 276.9868187848.

The spelling of 21250899 in words is "twenty-one million, two hundred fifty thousand, eight hundred ninety-nine".