691705949 has 4 divisors (see below), whose sum is σ = 754588320. Its totient is φ = 628823580.

The previous prime is 691705943. The next prime is 691705951. The reversal of 691705949 is 949507196.

691705949 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 691705949 - 2²⁴ = 674928733 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 691705897 and 691705906.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691705943) 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, 31441169 + ... + 31441190.

It is an arithmetic number, because the mean of its divisors is an integer number (188647080).

Almost surely, 2^691705949 is an apocalyptic number.

It is an amenable number.

691705949 is a deficient number, since it is larger than the sum of its proper divisors (62882371).

691705949 is a wasteful number, since it uses less digits than its factorization.

691705949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62882370.

The product of its (nonzero) digits is 612360, while the sum is 50.

The square root of 691705949 is about 26300.3032111799. The cubic root of 691705949 is about 884.3832399337.

The spelling of 691705949 in words is "six hundred ninety-one million, seven hundred five thousand, nine hundred forty-nine".