721349507 has 2 divisors, whose sum is σ = 721349508. Its totient is φ = 721349506.

The previous prime is 721349413. The next prime is 721349533. The reversal of 721349507 is 705943127.

It is a strong prime.

It is an emirp because it is prime and its reverse (705943127) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721349507 is a prime.

It is a super-2 number, since 2×721349507² = 1040690222498286098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (721349107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360674753 + 360674754.

It is an arithmetic number, because the mean of its divisors is an integer number (360674754).

Almost surely, 2^721349507 is an apocalyptic number.

721349507 is a deficient number, since it is larger than the sum of its proper divisors (1).

721349507 is an equidigital number, since it uses as much as digits as its factorization.

721349507 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52920, while the sum is 38.

The square root of 721349507 is about 26857.9505361076. The cubic root of 721349507 is about 896.8405708467.

The spelling of 721349507 in words is "seven hundred twenty-one million, three hundred forty-nine thousand, five hundred seven".