7081691977 has 2 divisors, whose sum is σ = 7081691978. Its totient is φ = 7081691976.

The previous prime is 7081691909. The next prime is 7081691983. The reversal of 7081691977 is 7791961807.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6564402441 + 517289536 = 81021^2 + 22744^2 .

It is a cyclic number.

It is not a de Polignac number, because 7081691977 - 2¹¹ = 7081689929 is a prime.

It is a super-2 number, since 2×7081691977² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7081691777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3540845988 + 3540845989.

It is an arithmetic number, because the mean of its divisors is an integer number (3540845989).

Almost surely, 2^7081691977 is an apocalyptic number.

It is an amenable number.

7081691977 is a deficient number, since it is larger than the sum of its proper divisors (1).

7081691977 is an equidigital number, since it uses as much as digits as its factorization.

7081691977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1333584, while the sum is 55.

The square root of 7081691977 is about 84152.7894784243. The cubic root of 7081691977 is about 1920.3439033318.

The spelling of 7081691977 in words is "seven billion, eighty-one million, six hundred ninety-one thousand, nine hundred seventy-seven".