688963621 has 4 divisors (see below), whose sum is σ = 689403744. Its totient is φ = 688523500.

The previous prime is 688963619. The next prime is 688963651. The reversal of 688963621 is 126369886.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 688963621 - 2¹ = 688963619 is a prime.

It is a super-2 number, since 2×688963621² = 949341742122863282, 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 (688963651) 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, 217705 + ... + 220846.

It is an arithmetic number, because the mean of its divisors is an integer number (172350936).

Almost surely, 2^688963621 is an apocalyptic number.

It is an amenable number.

688963621 is a deficient number, since it is larger than the sum of its proper divisors (440123).

688963621 is a wasteful number, since it uses less digits than its factorization.

688963621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440122.

The product of its digits is 746496, while the sum is 49.

The square root of 688963621 is about 26248.1165229050. The cubic root of 688963621 is about 883.2129540794.

The spelling of 688963621 in words is "six hundred eighty-eight million, nine hundred sixty-three thousand, six hundred twenty-one".