691748747 has 2 divisors, whose sum is σ = 691748748. Its totient is φ = 691748746.

The previous prime is 691748699. The next prime is 691748749. The reversal of 691748747 is 747847196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691748747 - 2¹⁰ = 691747723 is a prime.

Together with 691748749, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (691748749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345874373 + 345874374.

It is an arithmetic number, because the mean of its divisors is an integer number (345874374).

Almost surely, 2^691748747 is an apocalyptic number.

691748747 is a deficient number, since it is larger than the sum of its proper divisors (1).

691748747 is an equidigital number, since it uses as much as digits as its factorization.

691748747 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2370816, while the sum is 53.

The square root of 691748747 is about 26301.1168394044. The cubic root of 691748747 is about 884.4014794054.

The spelling of 691748747 in words is "six hundred ninety-one million, seven hundred forty-eight thousand, seven hundred forty-seven".