691111507 has 4 divisors (see below), whose sum is σ = 692497000. Its totient is φ = 689726016.

The previous prime is 691111501. The next prime is 691111511. The reversal of 691111507 is 705111196.

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

It is a cyclic number.

It is not a de Polignac number, because 691111507 - 2²³ = 682722899 is a prime.

It is a super-2 number, since 2×691111507² = 955270230215622098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691111501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 691998 + ... + 692995.

It is an arithmetic number, because the mean of its divisors is an integer number (173124250).

Almost surely, 2^691111507 is an apocalyptic number.

691111507 is a deficient number, since it is larger than the sum of its proper divisors (1385493).

691111507 is a wasteful number, since it uses less digits than its factorization.

691111507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1385492.

The product of its (nonzero) digits is 1890, while the sum is 31.

The square root of 691111507 is about 26288.9997337289. Note that the first 3 decimals coincide. The cubic root of 691111507 is about 884.1298253087.

The spelling of 691111507 in words is "six hundred ninety-one million, one hundred eleven thousand, five hundred seven".