66040822521 has 12 divisors (see below), whose sum is σ = 95394543972. Its totient is φ = 44026178976.

The previous prime is 66040822511. The next prime is 66040822531. The reversal of 66040822521 is 12522804066.

It is a happy number.

66040822521 is a `hidden beast` number, since 6 + 6 + 0 + 408 + 225 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (66040822511) and next prime (66040822531).

It can be written as a sum of positive squares in 2 ways, for example, as 57905684496 + 8135138025 = 240636^2 + 90195^2 .

It is not a de Polignac number, because 66040822521 - 2²⁶ = 65973713657 is a prime.

It is a super-2 number, since 2×66040822521² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66040822511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 631455 + ... + 728571.

It is an arithmetic number, because the mean of its divisors is an integer number (7949545331).

Almost surely, 2^66040822521 is an apocalyptic number.

It is an amenable number.

66040822521 is a deficient number, since it is larger than the sum of its proper divisors (29353721451).

66040822521 is a wasteful number, since it uses less digits than its factorization.

66040822521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172680 (or 172677 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The spelling of 66040822521 in words is "sixty-six billion, forty million, eight hundred twenty-two thousand, five hundred twenty-one".