21102013057 has 2 divisors, whose sum is σ = 21102013058. Its totient is φ = 21102013056.

The previous prime is 21102013013. The next prime is 21102013087. The reversal of 21102013057 is 75031020112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19057526401 + 2044486656 = 138049^2 + 45216^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21102013057 is a prime.

It is not a weakly prime, because it can be changed into another prime (21102013087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551006528 + 10551006529.

It is an arithmetic number, because the mean of its divisors is an integer number (10551006529).

Almost surely, 2^21102013057 is an apocalyptic number.

It is an amenable number.

21102013057 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102013057 is an equidigital number, since it uses as much as digits as its factorization.

21102013057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 420, while the sum is 22.

Adding to 21102013057 its reverse (75031020112), we get a palindrome (96133033169).

The spelling of 21102013057 in words is "twenty-one billion, one hundred two million, thirteen thousand, fifty-seven".