21250640053 has 2 divisors, whose sum is σ = 21250640054. Its totient is φ = 21250640052.

The previous prime is 21250640017. The next prime is 21250640071. The reversal of 21250640053 is 35004605212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16328495089 + 4922144964 = 127783^2 + 70158^2 .

It is a cyclic number.

It is not a de Polignac number, because 21250640053 - 2²⁵ = 21217085621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21250640153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10625320026 + 10625320027.

It is an arithmetic number, because the mean of its divisors is an integer number (10625320027).

Almost surely, 2^21250640053 is an apocalyptic number.

It is an amenable number.

21250640053 is a deficient number, since it is larger than the sum of its proper divisors (1).

21250640053 is an equidigital number, since it uses as much as digits as its factorization.

21250640053 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7200, while the sum is 28.

The spelling of 21250640053 in words is "twenty-one billion, two hundred fifty million, six hundred forty thousand, fifty-three".