3972261656369 has 2 divisors, whose sum is σ = 3972261656370. Its totient is φ = 3972261656368.

The previous prime is 3972261656353. The next prime is 3972261656371. The reversal of 3972261656369 is 9636561622793.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3718938687025 + 253322969344 = 1928455^2 + 503312^2 .

It is a cyclic number.

It is not a de Polignac number, because 3972261656369 - 2⁴ = 3972261656353 is a prime.

It is a super-3 number, since 3×3972261656369³ (a number of 39 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 3972261656371, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3972261656329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1986130828184 + 1986130828185.

It is an arithmetic number, because the mean of its divisors is an integer number (1986130828185).

Almost surely, 2^{3972261656369} is an apocalyptic number.

It is an amenable number.

3972261656369 is a deficient number, since it is larger than the sum of its proper divisors (1).

3972261656369 is an equidigital number, since it uses as much as digits as its factorization.

3972261656369 is an evil number, because the sum of its binary digits is even.

The product of its digits is 132269760, while the sum is 65.

The spelling of 3972261656369 in words is "three trillion, nine hundred seventy-two billion, two hundred sixty-one million, six hundred fifty-six thousand, three hundred sixty-nine".