721303997 has 4 divisors (see below), whose sum is σ = 721377216. Its totient is φ = 721230780.

The previous prime is 721303991. The next prime is 721304009. The reversal of 721303997 is 799303127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 721303997 - 2⁸ = 721303741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721303991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19013 + ... + 42474.

It is an arithmetic number, because the mean of its divisors is an integer number (180344304).

Almost surely, 2^721303997 is an apocalyptic number.

It is an amenable number.

721303997 is a deficient number, since it is larger than the sum of its proper divisors (73219).

721303997 is a wasteful number, since it uses less digits than its factorization.

721303997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73218.

The product of its (nonzero) digits is 71442, while the sum is 41.

The square root of 721303997 is about 26857.1032875848. The cubic root of 721303997 is about 896.8217098681.

The spelling of 721303997 in words is "seven hundred twenty-one million, three hundred three thousand, nine hundred ninety-seven".