691043963949 has 8 divisors (see below), whose sum is σ = 1023768835520. Its totient is φ = 460695975948.

The previous prime is 691043963881. The next prime is 691043963959. The reversal of 691043963949 is 949369340196.

It is not a de Polignac number, because 691043963949 - 2⁷ = 691043963821 is a prime.

It is a super-2 number, since 2×691043963949² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691043963959) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12797110417 + ... + 12797110470.

It is an arithmetic number, because the mean of its divisors is an integer number (127971104440).

Almost surely, 2^691043963949 is an apocalyptic number.

It is an amenable number.

691043963949 is a deficient number, since it is larger than the sum of its proper divisors (332724871571).

691043963949 is a wasteful number, since it uses less digits than its factorization.

691043963949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25594220896 (or 25594220890 counting only the distinct ones).

The product of its (nonzero) digits is 34012224, while the sum is 63.

The spelling of 691043963949 in words is "six hundred ninety-one billion, forty-three million, nine hundred sixty-three thousand, nine hundred forty-nine".