721447020 has 384 divisors, whose sum is σ = 2767564800. Its totient is φ = 152285184.

The previous prime is 721447019. The next prime is 721447057. The reversal of 721447020 is 20744127.

It is a happy number.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 6618726 + ... + 6618834.

It is an arithmetic number, because the mean of its divisors is an integer number (7207200).

Almost surely, 2^721447020 is an apocalyptic number.

721447020 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 721447020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1383782400).

721447020 is an abundant number, since it is smaller than the sum of its proper divisors (2046117780).

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

721447020 is a wasteful number, since it uses less digits than its factorization.

721447020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254 (or 246 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The square root of 721447020 is about 26859.7658217640. The cubic root of 721447020 is about 896.8809810655.

The spelling of 721447020 in words is "seven hundred twenty-one million, four hundred forty-seven thousand, twenty".