21248669537 has 2 divisors, whose sum is σ = 21248669538. Its totient is φ = 21248669536.

The previous prime is 21248669501. The next prime is 21248669549. The reversal of 21248669537 is 73596684212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21157447936 + 91221601 = 145456^2 + 9551^2 .

It is a cyclic number.

It is not a de Polignac number, because 21248669537 - 2²² = 21244475233 is a prime.

It is not a weakly prime, because it can be changed into another prime (21248669587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10624334768 + 10624334769.

It is an arithmetic number, because the mean of its divisors is an integer number (10624334769).

Almost surely, 2^21248669537 is an apocalyptic number.

It is an amenable number.

21248669537 is a deficient number, since it is larger than the sum of its proper divisors (1).

21248669537 is an equidigital number, since it uses as much as digits as its factorization.

21248669537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4354560, while the sum is 53.

The spelling of 21248669537 in words is "twenty-one billion, two hundred forty-eight million, six hundred sixty-nine thousand, five hundred thirty-seven".