721007136 has 192 divisors, whose sum is σ = 2235340800. Its totient is φ = 225462528.

The previous prime is 721007093. The next prime is 721007137. The reversal of 721007136 is 631700127.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (721007137) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2741341 + ... + 2741603.

It is an arithmetic number, because the mean of its divisors is an integer number (11642400).

Almost surely, 2^721007136 is an apocalyptic number.

721007136 is a gapful number since it is divisible by the number (76) 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 721007136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1117670400).

721007136 is an abundant number, since it is smaller than the sum of its proper divisors (1514333664).

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

721007136 is a wasteful number, since it uses less digits than its factorization.

721007136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 468 (or 454 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The square root of 721007136 is about 26851.5760431301. The cubic root of 721007136 is about 896.6986605377.

The spelling of 721007136 in words is "seven hundred twenty-one million, seven thousand, one hundred thirty-six".