7813692721 has 2 divisors, whose sum is σ = 7813692722. Its totient is φ = 7813692720.

The previous prime is 7813692673. The next prime is 7813692727. The reversal of 7813692721 is 1272963187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6687150625 + 1126542096 = 81775^2 + 33564^2 .

It is a cyclic number.

It is not a de Polignac number, because 7813692721 - 2¹⁷ = 7813561649 is a prime.

It is a super-2 number, since 2×7813692721² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7813692727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3906846360 + 3906846361.

It is an arithmetic number, because the mean of its divisors is an integer number (3906846361).

Almost surely, 2^7813692721 is an apocalyptic number.

It is an amenable number.

7813692721 is a deficient number, since it is larger than the sum of its proper divisors (1).

7813692721 is an equidigital number, since it uses as much as digits as its factorization.

7813692721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 254016, while the sum is 46.

The square root of 7813692721 is about 88395.0944396803. The cubic root of 7813692721 is about 1984.3522872391.

The spelling of 7813692721 in words is "seven billion, eight hundred thirteen million, six hundred ninety-two thousand, seven hundred twenty-one".