691387426 has 8 divisors (see below), whose sum is σ = 1037226780. Its totient is φ = 345645168.

The previous prime is 691387423. The next prime is 691387471. The reversal of 691387426 is 624783196.

It can be written as a sum of positive squares in 2 ways, for example, as 657153225 + 34234201 = 25635^2 + 5851^2 .

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

It is not an unprimeable number, because it can be changed into a prime (691387423) 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, 2601 + ... + 37276.

Almost surely, 2^691387426 is an apocalyptic number.

691387426 is a deficient number, since it is larger than the sum of its proper divisors (345839354).

691387426 is a wasteful number, since it uses less digits than its factorization.

691387426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48548.

The product of its digits is 435456, while the sum is 46.

The square root of 691387426 is about 26294.2470133678. The cubic root of 691387426 is about 884.2474694985.

The spelling of 691387426 in words is "six hundred ninety-one million, three hundred eighty-seven thousand, four hundred twenty-six".