691319440645 has 16 divisors (see below), whose sum is σ = 843725704320. Its totient is φ = 543629116864.

The previous prime is 691319440631. The next prime is 691319440697. The reversal of 691319440645 is 546044913196.

It is a cyclic number.

It is not a de Polignac number, because 691319440645 - 2¹⁹ = 691318916357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 691319440592 and 691319440601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3093672 + ... + 3309598.

It is an arithmetic number, because the mean of its divisors is an integer number (52732856520).

Almost surely, 2^691319440645 is an apocalyptic number.

It is an amenable number.

691319440645 is a deficient number, since it is larger than the sum of its proper divisors (152406263675).

691319440645 is a wasteful number, since it uses less digits than its factorization.

691319440645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226844.

The product of its (nonzero) digits is 2799360, while the sum is 52.

The spelling of 691319440645 in words is "six hundred ninety-one billion, three hundred nineteen million, four hundred forty thousand, six hundred forty-five".