21150023523569 has 2 divisors, whose sum is σ = 21150023523570. Its totient is φ = 21150023523568.

The previous prime is 21150023523557. The next prime is 21150023523589. The reversal of 21150023523569 is 96532532005112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20120383080625 + 1029640442944 = 4485575^2 + 1014712^2 .

It is a cyclic number.

It is not a de Polignac number, because 21150023523569 - 2¹² = 21150023519473 is a prime.

It is a super-2 number, since 2×21150023523569² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21150023523529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10575011761784 + 10575011761785.

It is an arithmetic number, because the mean of its divisors is an integer number (10575011761785).

Almost surely, 2^{21150023523569} is an apocalyptic number.

It is an amenable number.

21150023523569 is a deficient number, since it is larger than the sum of its proper divisors (1).

21150023523569 is an equidigital number, since it uses as much as digits as its factorization.

21150023523569 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486000, while the sum is 44.

The spelling of 21150023523569 in words is "twenty-one trillion, one hundred fifty billion, twenty-three million, five hundred twenty-three thousand, five hundred sixty-nine".