721881983 has 2 divisors, whose sum is σ = 721881984. Its totient is φ = 721881982.

The previous prime is 721881943. The next prime is 721882061. The reversal of 721881983 is 389188127.

It is a weak prime.

It is an emirp because it is prime and its reverse (389188127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721881983 - 2¹⁸ = 721619839 is a prime.

It is a super-2 number, since 2×721881983² = 1042227194760024578, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721881943) by changing a digit.

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 as a sum of consecutive naturals, namely, 360940991 + 360940992.

It is an arithmetic number, because the mean of its divisors is an integer number (360940992).

Almost surely, 2^721881983 is an apocalyptic number.

721881983 is a deficient number, since it is larger than the sum of its proper divisors (1).

721881983 is an equidigital number, since it uses as much as digits as its factorization.

721881983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 47.

The square root of 721881983 is about 26867.8615263664. The cubic root of 721881983 is about 897.0611891094.

The spelling of 721881983 in words is "seven hundred twenty-one million, eight hundred eighty-one thousand, nine hundred eighty-three".