21511010057 has 2 divisors, whose sum is σ = 21511010058. Its totient is φ = 21511010056.

The previous prime is 21511010041. The next prime is 21511010099. The reversal of 21511010057 is 75001011512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16799011321 + 4711998736 = 129611^2 + 68644^2 .

It is a cyclic number.

It is not a de Polignac number, because 21511010057 - 2⁴ = 21511010041 is a prime.

It is not a weakly prime, because it can be changed into another prime (21511010957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10755505028 + 10755505029.

It is an arithmetic number, because the mean of its divisors is an integer number (10755505029).

Almost surely, 2^21511010057 is an apocalyptic number.

It is an amenable number.

21511010057 is a deficient number, since it is larger than the sum of its proper divisors (1).

21511010057 is an equidigital number, since it uses as much as digits as its factorization.

21511010057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 350, while the sum is 23.

Adding to 21511010057 its reverse (75001011512), we get a palindrome (96512021569).

The spelling of 21511010057 in words is "twenty-one billion, five hundred eleven million, ten thousand, fifty-seven".