731365920 has 144 divisors (see below), whose sum is σ = 2520528192. Its totient is φ = 193098240.

The previous prime is 731365907. The next prime is 731365961. The reversal of 731365920 is 29563137.

731365920 is a `hidden beast` number, since 7 + 31 + 36 + 592 + 0 = 666.

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

It is a super-2 number, since 2×731365920² = 1069792217874892800, which contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 145855 + ... + 150785.

It is an arithmetic number, because the mean of its divisors is an integer number (17503668).

Almost surely, 2^731365920 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 731365920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1260264096).

731365920 is an abundant number, since it is smaller than the sum of its proper divisors (1789162272).

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

731365920 is a wasteful number, since it uses less digits than its factorization.

731365920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5055 (or 5044 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 36.

The square root of 731365920 is about 27043.7778426018. Note that the first 3 decimals coincide. The cubic root of 731365920 is about 900.9725782417.

The spelling of 731365920 in words is "seven hundred thirty-one million, three hundred sixty-five thousand, nine hundred twenty".