21524953 has 2 divisors, whose sum is σ = 21524954. Its totient is φ = 21524952.

The previous prime is 21524939. The next prime is 21524969. The reversal of 21524953 is 35942512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12446784 + 9078169 = 3528^2 + 3013^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21524953 is a prime.

It is not a weakly prime, because it can be changed into another prime (21524903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10762476 + 10762477.

It is an arithmetic number, because the mean of its divisors is an integer number (10762477).

Almost surely, 2^21524953 is an apocalyptic number.

It is an amenable number.

21524953 is a deficient number, since it is larger than the sum of its proper divisors (1).

21524953 is an equidigital number, since it uses as much as digits as its factorization.

21524953 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10800, while the sum is 31.

The square root of 21524953 is about 4639.4992186657. The cubic root of 21524953 is about 278.1724212033.

The spelling of 21524953 in words is "twenty-one million, five hundred twenty-four thousand, nine hundred fifty-three".