721378560 has 288 divisors, whose sum is σ = 2693763072. Its totient is φ = 161095680.

The previous prime is 721378547. The next prime is 721378589. The reversal of 721378560 is 65873127.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1263075 + ... + 1263645.

It is an arithmetic number, because the mean of its divisors is an integer number (9353344).

Almost surely, 2^721378560 is an apocalyptic number.

721378560 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721378560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1346881536).

721378560 is an abundant number, since it is smaller than the sum of its proper divisors (1972384512).

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

721378560 is a wasteful number, since it uses less digits than its factorization.

721378560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649 (or 635 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 39.

The square root of 721378560 is about 26858.4913947154. The cubic root of 721378560 is about 896.8526110385.

The spelling of 721378560 in words is "seven hundred twenty-one million, three hundred seventy-eight thousand, five hundred sixty".