721378368 has 84 divisors (see below), whose sum is σ = 2102845680. Its totient is φ = 236372736.

The previous prime is 721378349. The next prime is 721378369. The reversal of 721378368 is 863873127.

721378368 is a `hidden beast` number, since 7 + 213 + 78 + 368 = 666.

It is not an unprimeable number, because it can be changed into a prime (721378369) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23371 + ... + 44597.

Almost surely, 2^721378368 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 721378368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1051422840).

721378368 is an abundant number, since it is smaller than the sum of its proper divisors (1381467312).

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

721378368 is a wasteful number, since it uses less digits than its factorization.

721378368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21304 (or 21291 counting only the distinct ones).

The product of its digits is 338688, while the sum is 45.

The square root of 721378368 is about 26858.4878204265. The cubic root of 721378368 is about 896.8525314706.

The spelling of 721378368 in words is "seven hundred twenty-one million, three hundred seventy-eight thousand, three hundred sixty-eight".