689615522 has 18 divisors (see below), whose sum is σ = 1070655579. Its totient is φ = 333127860.

The previous prime is 689615519. The next prime is 689615561. The reversal of 689615522 is 225516986.

It can be written as a sum of positive squares in only one way, i.e., 344807761 + 344807761 = 18569^2 + 18569^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=18569.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1150979 + ... + 1151577.

Almost surely, 2^689615522 is an apocalyptic number.

689615522 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

689615522 is a deficient number, since it is larger than the sum of its proper divisors (381040057).

689615522 is an frugal number, since it uses more digits than its factorization.

689615522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1262 (or 632 counting only the distinct ones).

The product of its digits is 259200, while the sum is 44.

The square root of 689615522 is about 26260.5316397060. The cubic root of 689615522 is about 883.4914331784.

Multiplying 689615522 by its product of digits (259200), we get a square (178748343302400 = 13369680²).

The spelling of 689615522 in words is "six hundred eighty-nine million, six hundred fifteen thousand, five hundred twenty-two".