21599999969 has 2 divisors, whose sum is σ = 21599999970. Its totient is φ = 21599999968.

The previous prime is 21599999963. The next prime is 21600000017. The reversal of 21599999969 is 96999999512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21444673600 + 155326369 = 146440^2 + 12463^2 .

It is a cyclic number.

It is not a de Polignac number, because 21599999969 - 2⁸ = 21599999713 is a prime.

It is a super-2 number, since 2×21599999969² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21599999969.

It is not a weakly prime, because it can be changed into another prime (21599999963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10799999984 + 10799999985.

It is an arithmetic number, because the mean of its divisors is an integer number (10799999985).

Almost surely, 2^21599999969 is an apocalyptic number.

It is an amenable number.

21599999969 is a deficient number, since it is larger than the sum of its proper divisors (1).

21599999969 is an equidigital number, since it uses as much as digits as its factorization.

21599999969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 286978140, while the sum is 77.

The spelling of 21599999969 in words is "twenty-one billion, five hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred sixty-nine".