21054408569 has 2 divisors, whose sum is σ = 21054408570. Its totient is φ = 21054408568.

The previous prime is 21054408527. The next prime is 21054408577. The reversal of 21054408569 is 96580445012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20506240000 + 548168569 = 143200^2 + 23413^2 .

It is a cyclic number.

It is not a de Polignac number, because 21054408569 - 2⁸ = 21054408313 is a prime.

It is a super-2 number, since 2×21054408569² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21054408509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10527204284 + 10527204285.

It is an arithmetic number, because the mean of its divisors is an integer number (10527204285).

Almost surely, 2^21054408569 is an apocalyptic number.

It is an amenable number.

21054408569 is a deficient number, since it is larger than the sum of its proper divisors (1).

21054408569 is an equidigital number, since it uses as much as digits as its factorization.

21054408569 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 345600, while the sum is 44.

The spelling of 21054408569 in words is "twenty-one billion, fifty-four million, four hundred eight thousand, five hundred sixty-nine".