726721920 has 192 divisors, whose sum is σ = 2546238240. Its totient is φ = 190955520.

The previous prime is 726721909. The next prime is 726721949. The reversal of 726721920 is 29127627.

It is a tau number, because it is divible by the number of its divisors (192).

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

It is a congruent number.

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, 408072 + ... + 409848.

Almost surely, 2^726721920 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 726721920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1273119120).

726721920 is an abundant number, since it is smaller than the sum of its proper divisors (1819516320).

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

726721920 is a wasteful number, since it uses less digits than its factorization.

726721920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1873 (or 1858 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 726721920 is about 26957.7803240549. The cubic root of 726721920 is about 899.0615402957.

The spelling of 726721920 in words is "seven hundred twenty-six million, seven hundred twenty-one thousand, nine hundred twenty".