689481991 has 8 divisors (see below), whose sum is σ = 752857344. Its totient is φ = 626222520.

The previous prime is 689481979. The next prime is 689482009. The reversal of 689481991 is 199184986.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 689481991 - 2¹¹ = 689479943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689481941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16281 + ... + 40546.

It is an arithmetic number, because the mean of its divisors is an integer number (94107168).

Almost surely, 2^689481991 is an apocalyptic number.

689481991 is a deficient number, since it is larger than the sum of its proper divisors (63375353).

689481991 is a wasteful number, since it uses less digits than its factorization.

689481991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57941.

The product of its digits is 1119744, while the sum is 55.

The square root of 689481991 is about 26257.9890890373. The cubic root of 689481991 is about 883.4344056967.

The spelling of 689481991 in words is "six hundred eighty-nine million, four hundred eighty-one thousand, nine hundred ninety-one".