721497340 has 48 divisors (see below), whose sum is σ = 1606500000. Its totient is φ = 271245312.

The previous prime is 721497319. The next prime is 721497341. The reversal of 721497340 is 43794127.

It is a self number, because there is not a number n which added to its sum of digits gives 721497340.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721497341) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 423811 + ... + 425509.

It is an arithmetic number, because the mean of its divisors is an integer number (33468750).

Almost surely, 2^721497340 is an apocalyptic number.

It is an amenable number.

721497340 is an abundant number, since it is smaller than the sum of its proper divisors (885002660).

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

721497340 is a wasteful number, since it uses less digits than its factorization.

721497340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2974 (or 2972 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 37.

The square root of 721497340 is about 26860.7025224583. The cubic root of 721497340 is about 896.9018326783.

The spelling of 721497340 in words is "seven hundred twenty-one million, four hundred ninety-seven thousand, three hundred forty".