691440938 has 8 divisors (see below), whose sum is σ = 1052641632. Its totient is φ = 340560396.

The previous prime is 691440899. The next prime is 691440961. The reversal of 691440938 is 839044196.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2579870 + ... + 2580137.

It is an arithmetic number, because the mean of its divisors is an integer number (131580204).

Almost surely, 2^691440938 is an apocalyptic number.

691440938 is a deficient number, since it is larger than the sum of its proper divisors (361200694).

691440938 is a wasteful number, since it uses less digits than its factorization.

691440938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5160076.

The product of its (nonzero) digits is 186624, while the sum is 44.

The square root of 691440938 is about 26295.2645546684. The cubic root of 691440938 is about 884.2702819035.

The spelling of 691440938 in words is "six hundred ninety-one million, four hundred forty thousand, nine hundred thirty-eight".