691001438 has 4 divisors (see below), whose sum is σ = 1036502160. Its totient is φ = 345500718.

The previous prime is 691001417. The next prime is 691001449. The reversal of 691001438 is 834100196.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172750358 + ... + 172750361.

It is an arithmetic number, because the mean of its divisors is an integer number (259125540).

Almost surely, 2^691001438 is an apocalyptic number.

691001438 is a deficient number, since it is larger than the sum of its proper divisors (345500722).

691001438 is a wasteful number, since it uses less digits than its factorization.

691001438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345500721.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 691001438 is about 26286.9062082247. The cubic root of 691001438 is about 884.0828862106.

The spelling of 691001438 in words is "six hundred ninety-one million, one thousand, four hundred thirty-eight".