723157920 has 144 divisors (see below), whose sum is σ = 2553019560. Its totient is φ = 186181632.

The previous prime is 723157907. The next prime is 723157921. The reversal of 723157920 is 29751327.

It can be written as a sum of positive squares in 4 ways, for example, as 676208016 + 46949904 = 26004^2 + 6852^2 .

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

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (723157921) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33102 + ... + 50418.

Almost surely, 2^723157920 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 723157920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1276509780).

723157920 is an abundant number, since it is smaller than the sum of its proper divisors (1829861640).

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

723157920 is a wasteful number, since it uses less digits than its factorization.

723157920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17367 (or 17356 counting only the distinct ones).

The product of its (nonzero) digits is 26460, while the sum is 36.

The square root of 723157920 is about 26891.5957131592. The cubic root of 723157920 is about 897.5894009634.

The spelling of 723157920 in words is "seven hundred twenty-three million, one hundred fifty-seven thousand, nine hundred twenty".