689256864 has 144 divisors (see below), whose sum is σ = 2050671168. Its totient is φ = 227722752.

The previous prime is 689256839. The next prime is 689256889. The reversal of 689256864 is 468652986.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (689256839) and next prime (689256889).

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×689256864² = 950150049142228992, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 689256864.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1064989 + ... + 1065635.

It is an arithmetic number, because the mean of its divisors is an integer number (14240772).

Almost surely, 2^689256864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 689256864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1025335584).

689256864 is an abundant number, since it is smaller than the sum of its proper divisors (1361414304).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

689256864 is a wasteful number, since it uses less digits than its factorization.

689256864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 809 (or 789 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 54.

The square root of 689256864 is about 26253.7019103973. The cubic root of 689256864 is about 883.3382433650.

The spelling of 689256864 in words is "six hundred eighty-nine million, two hundred fifty-six thousand, eight hundred sixty-four".