691072771 has 2 divisors, whose sum is σ = 691072772. Its totient is φ = 691072770.

The previous prime is 691072751. The next prime is 691072783. The reversal of 691072771 is 177270196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691072771 - 2⁹ = 691072259 is a prime.

It is not a weakly prime, because it can be changed into another prime (691072751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345536385 + 345536386.

It is an arithmetic number, because the mean of its divisors is an integer number (345536386).

Almost surely, 2^691072771 is an apocalyptic number.

691072771 is a deficient number, since it is larger than the sum of its proper divisors (1).

691072771 is an equidigital number, since it uses as much as digits as its factorization.

691072771 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37044, while the sum is 40.

The square root of 691072771 is about 26288.2629894027. The cubic root of 691072771 is about 884.1133068490.

The spelling of 691072771 in words is "six hundred ninety-one million, seventy-two thousand, seven hundred seventy-one".