721501457994 has 64 divisors (see below), whose sum is σ = 1632336773760. Its totient is φ = 236163600000.

The previous prime is 721501457921. The next prime is 721501458023. The reversal of 721501457994 is 499754105127.

721501457994 is a `hidden beast` number, since 7 + 2 + 1 + 50 + 14 + 579 + 9 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 721501457994.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1797469 + ... + 2161919.

It is an arithmetic number, because the mean of its divisors is an integer number (25505262090).

Almost surely, 2^721501457994 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721501457994, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (816168386880).

721501457994 is an abundant number, since it is smaller than the sum of its proper divisors (910835315766).

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

721501457994 is a wasteful number, since it uses less digits than its factorization.

721501457994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365124 (or 365118 counting only the distinct ones).

The product of its (nonzero) digits is 3175200, while the sum is 54.

The spelling of 721501457994 in words is "seven hundred twenty-one billion, five hundred one million, four hundred fifty-seven thousand, nine hundred ninety-four".