691480555 has 4 divisors (see below), whose sum is σ = 829776672. Its totient is φ = 553184440.

The previous prime is 691480529. The next prime is 691480577. The reversal of 691480555 is 555084196.

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

It is not a de Polignac number, because 691480555 - 2⁵ = 691480523 is a prime.

It is a Duffinian number.

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, 69148051 + ... + 69148060.

It is an arithmetic number, because the mean of its divisors is an integer number (207444168).

Almost surely, 2^691480555 is an apocalyptic number.

691480555 is a deficient number, since it is larger than the sum of its proper divisors (138296117).

691480555 is a wasteful number, since it uses less digits than its factorization.

691480555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138296116.

The product of its (nonzero) digits is 216000, while the sum is 43.

The square root of 691480555 is about 26296.0178544205. The cubic root of 691480555 is about 884.2871700496.

The spelling of 691480555 in words is "six hundred ninety-one million, four hundred eighty thousand, five hundred fifty-five".