685138944 has 176 divisors, whose sum is σ = 2110800896. Its totient is φ = 193536000.

The previous prime is 685138939. The next prime is 685138957. The reversal of 685138944 is 449831586.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 685138893 and 685138902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3246999 + ... + 3247209.

Almost surely, 2^685138944 is an apocalyptic number.

685138944 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 685138944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1055400448).

685138944 is an abundant number, since it is smaller than the sum of its proper divisors (1425661952).

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

685138944 is a wasteful number, since it uses less digits than its factorization.

685138944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392 (or 374 counting only the distinct ones).

The product of its digits is 829440, while the sum is 48.

The square root of 685138944 is about 26175.1589106924. The cubic root of 685138944 is about 881.5755795533.

The spelling of 685138944 in words is "six hundred eighty-five million, one hundred thirty-eight thousand, nine hundred forty-four".