691391742 has 8 divisors (see below), whose sum is σ = 1382783496. Its totient is φ = 230463912.

The previous prime is 691391719. The next prime is 691391749. The reversal of 691391742 is 247193196.

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

691391742 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 691391694 and 691391703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691391749) 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, 57615973 + ... + 57615984.

It is an arithmetic number, because the mean of its divisors is an integer number (172847937).

Almost surely, 2^691391742 is an apocalyptic number.

691391742 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

691391742 is a wasteful number, since it uses less digits than its factorization.

691391742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115231962.

The product of its digits is 81648, while the sum is 42.

The square root of 691391742 is about 26294.3290844243. The cubic root of 691391742 is about 884.2493094723.

The spelling of 691391742 in words is "six hundred ninety-one million, three hundred ninety-one thousand, seven hundred forty-two".