31661239669 has 2 divisors, whose sum is σ = 31661239670. Its totient is φ = 31661239668.

The previous prime is 31661239639. The next prime is 31661239691. The reversal of 31661239669 is 96693216613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20345599044 + 11315640625 = 142638^2 + 106375^2 .

It is a cyclic number.

It is not a de Polignac number, because 31661239669 - 2⁷ = 31661239541 is a prime.

It is a super-2 number, since 2×31661239669² (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 (31661239639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15830619834 + 15830619835.

It is an arithmetic number, because the mean of its divisors is an integer number (15830619835).

Almost surely, 2^31661239669 is an apocalyptic number.

It is an amenable number.

31661239669 is a deficient number, since it is larger than the sum of its proper divisors (1).

31661239669 is an equidigital number, since it uses as much as digits as its factorization.

31661239669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1889568, while the sum is 52.

The spelling of 31661239669 in words is "thirty-one billion, six hundred sixty-one million, two hundred thirty-nine thousand, six hundred sixty-nine".