691428244957 has 4 divisors (see below), whose sum is σ = 691432236000. Its totient is φ = 691424253916.

The previous prime is 691428244933. The next prime is 691428244963. The reversal of 691428244957 is 759442824196.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-691428244957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 691428244895 and 691428244904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691428244967) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1723273 + ... + 2086270.

It is an arithmetic number, because the mean of its divisors is an integer number (172858059000).

Almost surely, 2^691428244957 is an apocalyptic number.

It is an amenable number.

691428244957 is a deficient number, since it is larger than the sum of its proper divisors (3991043).

691428244957 is a wasteful number, since it uses less digits than its factorization.

691428244957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3991042.

The product of its digits is 34836480, while the sum is 61.

The spelling of 691428244957 in words is "six hundred ninety-one billion, four hundred twenty-eight million, two hundred forty-four thousand, nine hundred fifty-seven".