723566981 has 2 divisors, whose sum is σ = 723566982. Its totient is φ = 723566980.

The previous prime is 723566957. The next prime is 723566989. The reversal of 723566981 is 189665327.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 674440900 + 49126081 = 25970^2 + 7009^2 .

It is an emirp because it is prime and its reverse (189665327) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 723566981 - 2⁶ = 723566917 is a prime.

It is a super-2 number, since 2×723566981² = 1047098351986908722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (723566989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 361783490 + 361783491.

It is an arithmetic number, because the mean of its divisors is an integer number (361783491).

Almost surely, 2^723566981 is an apocalyptic number.

It is an amenable number.

723566981 is a deficient number, since it is larger than the sum of its proper divisors (1).

723566981 is an equidigital number, since it uses as much as digits as its factorization.

723566981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 544320, while the sum is 47.

The square root of 723566981 is about 26899.2003784499. The cubic root of 723566981 is about 897.7586123250.

The spelling of 723566981 in words is "seven hundred twenty-three million, five hundred sixty-six thousand, nine hundred eighty-one".