8121637669 has 2 divisors, whose sum is σ = 8121637670. Its totient is φ = 8121637668.

The previous prime is 8121637651. The next prime is 8121637697. The reversal of 8121637669 is 9667361218.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7201728769 + 919908900 = 84863^2 + 30330^2 .

It is a cyclic number.

It is not a de Polignac number, because 8121637669 - 2¹⁹ = 8121113381 is a prime.

It is a super-2 number, since 2×8121637669² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8121637649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4060818834 + 4060818835.

It is an arithmetic number, because the mean of its divisors is an integer number (4060818835).

Almost surely, 2^8121637669 is an apocalyptic number.

It is an amenable number.

8121637669 is a deficient number, since it is larger than the sum of its proper divisors (1).

8121637669 is an equidigital number, since it uses as much as digits as its factorization.

8121637669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 49.

The square root of 8121637669 is about 90120.1290999963. The cubic root of 8121637669 is about 2010.0855279894.

The spelling of 8121637669 in words is "eight billion, one hundred twenty-one million, six hundred thirty-seven thousand, six hundred sixty-nine".