691238461 has 4 divisors (see below), whose sum is σ = 715074300. Its totient is φ = 667402624.

The previous prime is 691238453. The next prime is 691238467. The reversal of 691238461 is 164832196.

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

It can be written as a sum of positive squares in 2 ways, for example, as 413349561 + 277888900 = 20331^2 + 16670^2 .

It is a cyclic number.

It is not a de Polignac number, because 691238461 - 2³ = 691238453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691238467) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 11917876 + ... + 11917933.

It is an arithmetic number, because the mean of its divisors is an integer number (178768575).

Almost surely, 2^691238461 is an apocalyptic number.

It is an amenable number.

691238461 is a deficient number, since it is larger than the sum of its proper divisors (23835839).

691238461 is a wasteful number, since it uses less digits than its factorization.

691238461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23835838.

The product of its digits is 62208, while the sum is 40.

The square root of 691238461 is about 26291.4142069231. The cubic root of 691238461 is about 884.1839588528.

The spelling of 691238461 in words is "six hundred ninety-one million, two hundred thirty-eight thousand, four hundred sixty-one".