691919747 has 2 divisors, whose sum is σ = 691919748. Its totient is φ = 691919746.

The previous prime is 691919699. The next prime is 691919773. The reversal of 691919747 is 747919196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691919747 - 2¹⁴ = 691903363 is a prime.

It is not a weakly prime, because it can be changed into another prime (691919777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345959873 + 345959874.

It is an arithmetic number, because the mean of its divisors is an integer number (345959874).

Almost surely, 2^691919747 is an apocalyptic number.

691919747 is a deficient number, since it is larger than the sum of its proper divisors (1).

691919747 is an equidigital number, since it uses as much as digits as its factorization.

691919747 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 857304, while the sum is 53.

The square root of 691919747 is about 26304.3674510527. The cubic root of 691919747 is about 884.4743479596.

The spelling of 691919747 in words is "six hundred ninety-one million, nine hundred nineteen thousand, seven hundred forty-seven".