21075011497 has 2 divisors, whose sum is σ = 21075011498. Its totient is φ = 21075011496.

The previous prime is 21075011491. The next prime is 21075011513. The reversal of 21075011497 is 79411057012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20169964441 + 905047056 = 142021^2 + 30084^2 .

It is a cyclic number.

It is not a de Polignac number, because 21075011497 - 2⁷ = 21075011369 is a prime.

It is a super-2 number, since 2×21075011497² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21075011491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10537505748 + 10537505749.

It is an arithmetic number, because the mean of its divisors is an integer number (10537505749).

Almost surely, 2^21075011497 is an apocalyptic number.

It is an amenable number.

21075011497 is a deficient number, since it is larger than the sum of its proper divisors (1).

21075011497 is an equidigital number, since it uses as much as digits as its factorization.

21075011497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17640, while the sum is 37.

The spelling of 21075011497 in words is "twenty-one billion, seventy-five million, eleven thousand, four hundred ninety-seven".