74672216561 has 2 divisors, whose sum is σ = 74672216562. Its totient is φ = 74672216560.

The previous prime is 74672216557. The next prime is 74672216573. The reversal of 74672216561 is 16561227647.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49131382336 + 25540834225 = 221656^2 + 159815^2 .

It is a cyclic number.

It is not a de Polignac number, because 74672216561 - 2² = 74672216557 is a prime.

It is a super-2 number, since 2×74672216561² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (74672216501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37336108280 + 37336108281.

It is an arithmetic number, because the mean of its divisors is an integer number (37336108281).

Almost surely, 2^74672216561 is an apocalyptic number.

It is an amenable number.

74672216561 is a deficient number, since it is larger than the sum of its proper divisors (1).

74672216561 is an equidigital number, since it uses as much as digits as its factorization.

74672216561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 846720, while the sum is 47.

The spelling of 74672216561 in words is "seventy-four billion, six hundred seventy-two million, two hundred sixteen thousand, five hundred sixty-one".