21250953 has 12 divisors (see below), whose sum is σ = 30787380. Its totient is φ = 14125056.

The previous prime is 21250877. The next prime is 21250961. The reversal of 21250953 is 35905212.

It can be written as a sum of positive squares in 2 ways, for example, as 13483584 + 7767369 = 3672^2 + 2787^2 .

It is not a de Polignac number, because 21250953 - 2¹⁰ = 21249929 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21250253) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 168 + ... + 6521.

It is an arithmetic number, because the mean of its divisors is an integer number (2565615).

Almost surely, 2^21250953 is an apocalyptic number.

It is an amenable number.

21250953 is a deficient number, since it is larger than the sum of its proper divisors (9536427).

21250953 is a wasteful number, since it uses less digits than its factorization.

21250953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7048 (or 7045 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 21250953 is about 4609.8755948507. The cubic root of 21250953 is about 276.9870533988.

The spelling of 21250953 in words is "twenty-one million, two hundred fifty thousand, nine hundred fifty-three".