721255500 has 216 divisors, whose sum is σ = 2647610784. Its totient is φ = 164808000.

The previous prime is 721255463. The next prime is 721255501. The reversal of 721255500 is 5552127.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (721255501) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 218865 + ... + 222135.

Almost surely, 2^721255500 is an apocalyptic number.

721255500 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 721255500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1323805392).

721255500 is an abundant number, since it is smaller than the sum of its proper divisors (1926355284).

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

721255500 is a wasteful number, since it uses less digits than its factorization.

721255500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3310 (or 3288 counting only the distinct ones).

The product of its (nonzero) digits is 3500, while the sum is 27.

The square root of 721255500 is about 26856.2004013971. The cubic root of 721255500 is about 896.8016100963.

The spelling of 721255500 in words is "seven hundred twenty-one million, two hundred fifty-five thousand, five hundred".