688977967 has 4 divisors (see below), whose sum is σ = 691860960. Its totient is φ = 686094976.

The previous prime is 688977959. The next prime is 688978009. The reversal of 688977967 is 769779886.

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 688977967 - 2³ = 688977959 is a prime.

It is a super-2 number, since 2×688977967² = 949381278022906178, which 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 (688977067) 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, 1441138 + ... + 1441615.

It is an arithmetic number, because the mean of its divisors is an integer number (172965240).

Almost surely, 2^688977967 is an apocalyptic number.

688977967 is a deficient number, since it is larger than the sum of its proper divisors (2882993).

688977967 is a wasteful number, since it uses less digits than its factorization.

688977967 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2882992.

The product of its digits is 64012032, while the sum is 67.

The square root of 688977967 is about 26248.3897982333. The cubic root of 688977967 is about 883.2190842943.

The spelling of 688977967 in words is "six hundred eighty-eight million, nine hundred seventy-seven thousand, nine hundred sixty-seven".