721132740 has 48 divisors (see below), whose sum is σ = 2243525760. Its totient is φ = 192301920.

The previous prime is 721132721. The next prime is 721132759. The reversal of 721132740 is 47231127.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (721132721) and next prime (721132759).

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 (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 667176 + ... + 668255.

It is an arithmetic number, because the mean of its divisors is an integer number (46740120).

Almost surely, 2^721132740 is an apocalyptic number.

It is an amenable number.

721132740 is an abundant number, since it is smaller than the sum of its proper divisors (1522393020).

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

721132740 is a wasteful number, since it uses less digits than its factorization.

721132740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1335449 (or 1335441 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 721132740 is about 26853.9147984051. The cubic root of 721132740 is about 896.7507277057.

Adding to 721132740 its reverse (47231127), we get a palindrome (768363867).

The spelling of 721132740 in words is "seven hundred twenty-one million, one hundred thirty-two thousand, seven hundred forty".