721189465920 has 2688 divisors, whose sum is σ = 3506988810240. Its totient is φ = 136492646400.

The previous prime is 721189465877. The next prime is 721189465963. The reversal of 721189465920 is 29564981127.

It is a happy number.

721189465920 is a `hidden beast` number, since 7 + 2 + 1 + 1 + 8 + 9 + 46 + 592 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (721189465877) and next prime (721189465963).

It is a super-2 number, since 2×721189465920² (a number of 25 digits) contains 22 as substring.

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

It is a congruent number.

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 383 ways as a sum of consecutive naturals, for example, 23264176305 + ... + 23264176335.

Almost surely, 2^721189465920 is an apocalyptic number.

721189465920 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 721189465920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1753494405120).

721189465920 is an abundant number, since it is smaller than the sum of its proper divisors (2785799344320).

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

721189465920 is a wasteful number, since it uses less digits than its factorization.

721189465920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 54.

The spelling of 721189465920 in words is "seven hundred twenty-one billion, one hundred eighty-nine million, four hundred sixty-five thousand, nine hundred twenty".