111664510621 has 2 divisors, whose sum is σ = 111664510622. Its totient is φ = 111664510620.

The previous prime is 111664510613. The next prime is 111664510631. The reversal of 111664510621 is 126015466111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102675384900 + 8989125721 = 320430^2 + 94811^2 .

It is a cyclic number.

It is not a de Polignac number, because 111664510621 - 2³ = 111664510613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111664510631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55832255310 + 55832255311.

It is an arithmetic number, because the mean of its divisors is an integer number (55832255311).

Almost surely, 2^111664510621 is an apocalyptic number.

It is an amenable number.

111664510621 is a deficient number, since it is larger than the sum of its proper divisors (1).

111664510621 is an equidigital number, since it uses as much as digits as its factorization.

111664510621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 34.

Adding to 111664510621 its reverse (126015466111), we get a palindrome (237679976732).

The spelling of 111664510621 in words is "one hundred eleven billion, six hundred sixty-four million, five hundred ten thousand, six hundred twenty-one".