691994897 has 16 divisors (see below), whose sum is σ = 791959680. Its totient is φ = 598819200.

The previous prime is 691994887. The next prime is 691994899. The reversal of 691994897 is 798499196.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 691994897 - 2⁴ = 691994881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691994899) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7373 + ... + 37925.

It is an arithmetic number, because the mean of its divisors is an integer number (49497480).

Almost surely, 2^691994897 is an apocalyptic number.

It is an amenable number.

691994897 is a deficient number, since it is larger than the sum of its proper divisors (99964783).

691994897 is a wasteful number, since it uses less digits than its factorization.

691994897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30664.

The product of its digits is 8817984, while the sum is 62.

The square root of 691994897 is about 26305.7958822766. The cubic root of 691994897 is about 884.5063679741.

The spelling of 691994897 in words is "six hundred ninety-one million, nine hundred ninety-four thousand, eight hundred ninety-seven".