8131029661 has 2 divisors, whose sum is σ = 8131029662. Its totient is φ = 8131029660.

The previous prime is 8131029653. The next prime is 8131029691. The reversal of 8131029661 is 1669201318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6032473561 + 2098556100 = 77669^2 + 45810^2 .

It is a cyclic number.

It is not a de Polignac number, because 8131029661 - 2³ = 8131029653 is a prime.

It is a super-2 number, since 2×8131029661² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 8131029661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8131029631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4065514830 + 4065514831.

It is an arithmetic number, because the mean of its divisors is an integer number (4065514831).

Almost surely, 2^8131029661 is an apocalyptic number.

It is an amenable number.

8131029661 is a deficient number, since it is larger than the sum of its proper divisors (1).

8131029661 is an equidigital number, since it uses as much as digits as its factorization.

8131029661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 8131029661 is about 90172.2222250289. Note that the first 5 decimals coincide. The cubic root of 8131029661 is about 2010.8600612147.

The spelling of 8131029661 in words is "eight billion, one hundred thirty-one million, twenty-nine thousand, six hundred sixty-one".