721091280 has 320 divisors, whose sum is σ = 2782821888. Its totient is φ = 150405120.

The previous prime is 721091257. The next prime is 721091323. The reversal of 721091280 is 82190127.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2991960 + ... + 2992200.

Almost surely, 2^721091280 is an apocalyptic number.

721091280 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 721091280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1391410944).

721091280 is an abundant number, since it is smaller than the sum of its proper divisors (2061730608).

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

721091280 is a wasteful number, since it uses less digits than its factorization.

721091280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414 (or 408 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 721091280 is about 26853.1428328231. The cubic root of 721091280 is about 896.7335417816.

The spelling of 721091280 in words is "seven hundred twenty-one million, ninety-one thousand, two hundred eighty".