688402845 has 48 divisors (see below), whose sum is σ = 1360627632. Its totient is φ = 318965760.

The previous prime is 688402831. The next prime is 688402853. The reversal of 688402845 is 548204886.

It can be written as a sum of positive squares in 8 ways, for example, as 16867449 + 671535396 = 4107^2 + 25914^2 .

It is not a de Polignac number, because 688402845 - 2⁷ = 688402717 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 688402845.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 24666 + ... + 44555.

It is an arithmetic number, because the mean of its divisors is an integer number (28346409).

Almost surely, 2^688402845 is an apocalyptic number.

688402845 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

688402845 is a deficient number, since it is larger than the sum of its proper divisors (672224787).

688402845 is a wasteful number, since it uses less digits than its factorization.

688402845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69262 (or 69259 counting only the distinct ones).

The product of its (nonzero) digits is 491520, while the sum is 45.

The square root of 688402845 is about 26237.4321342619. The cubic root of 688402845 is about 882.9732611790.

The spelling of 688402845 in words is "six hundred eighty-eight million, four hundred two thousand, eight hundred forty-five".