689582428921 has 3 divisors (see below), whose sum is σ = 689583259333. Its totient is φ = 689581598510.

The previous prime is 689582428903. The next prime is 689582428943. The reversal of 689582428921 is 129824285986.

The square root of 689582428921 is 830411.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 129824285986 = 2 ⋅64912142993.

It is not a de Polignac number, because 689582428921 - 2⁵ = 689582428889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (689582428121) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 415206 + ... + 1245616.

Almost surely, 2^689582428921 is an apocalyptic number.

689582428921 is the 830411-st square number.

689582428921 is the 415206-th centered octagonal number.

It is an amenable number.

689582428921 is a deficient number, since it is larger than the sum of its proper divisors (830412).

689582428921 is an frugal number, since it uses more digits than its factorization.

689582428921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1660822 (or 830411 counting only the distinct ones).

The product of its digits is 39813120, while the sum is 64.

Multiplying 689582428921 by its sum of digits (64), we get a square (44133275450944 = 6643288²).

The spelling of 689582428921 in words is "six hundred eighty-nine billion, five hundred eighty-two million, four hundred twenty-eight thousand, nine hundred twenty-one".