726685638 has 64 divisors (see below), whose sum is σ = 1799677440. Its totient is φ = 190858752.

The previous prime is 726685633. The next prime is 726685691. The reversal of 726685638 is 836586627.

726685638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (726685633) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18868 + ... + 42536.

It is an arithmetic number, because the mean of its divisors is an integer number (28119960).

Almost surely, 2^726685638 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 726685638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (899838720).

726685638 is an abundant number, since it is smaller than the sum of its proper divisors (1072991802).

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

726685638 is a wasteful number, since it uses less digits than its factorization.

726685638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23741.

The product of its digits is 2903040, while the sum is 51.

The square root of 726685638 is about 26957.1073744940. The cubic root of 726685638 is about 899.0465779960.

The spelling of 726685638 in words is "seven hundred twenty-six million, six hundred eighty-five thousand, six hundred thirty-eight".