21056603297 has 2 divisors, whose sum is σ = 21056603298. Its totient is φ = 21056603296.

The previous prime is 21056603261. The next prime is 21056603317. The reversal of 21056603297 is 79230665012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19962581521 + 1094021776 = 141289^2 + 33076^2 .

It is a cyclic number.

It is not a de Polignac number, because 21056603297 - 2⁶ = 21056603233 is a prime.

It is not a weakly prime, because it can be changed into another prime (21056603497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10528301648 + 10528301649.

It is an arithmetic number, because the mean of its divisors is an integer number (10528301649).

Almost surely, 2^21056603297 is an apocalyptic number.

It is an amenable number.

21056603297 is a deficient number, since it is larger than the sum of its proper divisors (1).

21056603297 is an equidigital number, since it uses as much as digits as its factorization.

21056603297 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 136080, while the sum is 41.

The spelling of 21056603297 in words is "twenty-one billion, fifty-six million, six hundred three thousand, two hundred ninety-seven".