691538735971 has 2 divisors, whose sum is σ = 691538735972. Its totient is φ = 691538735970.

The previous prime is 691538735911. The next prime is 691538735977. The reversal of 691538735971 is 179537835196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691538735971 - 2⁷ = 691538735843 is a prime.

It is not a weakly prime, because it can be changed into another prime (691538735977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345769367985 + 345769367986.

It is an arithmetic number, because the mean of its divisors is an integer number (345769367986).

Almost surely, 2^691538735971 is an apocalyptic number.

691538735971 is a deficient number, since it is larger than the sum of its proper divisors (1).

691538735971 is an equidigital number, since it uses as much as digits as its factorization.

691538735971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42865200, while the sum is 64.

The spelling of 691538735971 in words is "six hundred ninety-one billion, five hundred thirty-eight million, seven hundred thirty-five thousand, nine hundred seventy-one".