721502748391 has 2 divisors, whose sum is σ = 721502748392. Its totient is φ = 721502748390.

The previous prime is 721502748371. The next prime is 721502748467. The reversal of 721502748391 is 193847205127.

It is a weak prime.

It is an emirp because it is prime and its reverse (193847205127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721502748391 - 2²⁵ = 721469193959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721502748301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360751374195 + 360751374196.

It is an arithmetic number, because the mean of its divisors is an integer number (360751374196).

Almost surely, 2^721502748391 is an apocalyptic number.

721502748391 is a deficient number, since it is larger than the sum of its proper divisors (1).

721502748391 is an equidigital number, since it uses as much as digits as its factorization.

721502748391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 846720, while the sum is 49.

The spelling of 721502748391 in words is "seven hundred twenty-one billion, five hundred two million, seven hundred forty-eight thousand, three hundred ninety-one".