66572623661 has 2 divisors, whose sum is σ = 66572623662. Its totient is φ = 66572623660.

The previous prime is 66572623639. The next prime is 66572623687. The reversal of 66572623661 is 16632627566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66458262025 + 114361636 = 257795^2 + 10694^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66572623661 is a prime.

It is a super-2 number, since 2×66572623661² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66572629661) 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, 33286311830 + 33286311831.

It is an arithmetic number, because the mean of its divisors is an integer number (33286311831).

Almost surely, 2^66572623661 is an apocalyptic number.

It is an amenable number.

66572623661 is a deficient number, since it is larger than the sum of its proper divisors (1).

66572623661 is an equidigital number, since it uses as much as digits as its factorization.

66572623661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3265920, while the sum is 50.

The spelling of 66572623661 in words is "sixty-six billion, five hundred seventy-two million, six hundred twenty-three thousand, six hundred sixty-one".