691444243 has 24 divisors (see below), whose sum is σ = 835246080. Its totient is φ = 570119760.

The previous prime is 691444217. The next prime is 691444279. The reversal of 691444243 is 342444196.

It is a de Polignac number, because none of the positive numbers 2^k-691444243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691444543) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 270630 + ... + 273172.

It is an arithmetic number, because the mean of its divisors is an integer number (34801920).

Almost surely, 2^691444243 is an apocalyptic number.

691444243 is a deficient number, since it is larger than the sum of its proper divisors (143801837).

691444243 is a wasteful number, since it uses less digits than its factorization.

691444243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2767 (or 2760 counting only the distinct ones).

The product of its digits is 82944, while the sum is 37.

The square root of 691444243 is about 26295.3273986083. The cubic root of 691444243 is about 884.2716908012.

The spelling of 691444243 in words is "six hundred ninety-one million, four hundred forty-four thousand, two hundred forty-three".