1623664008991 has 2 divisors, whose sum is σ = 1623664008992. Its totient is φ = 1623664008990.

The previous prime is 1623664008983. The next prime is 1623664009001. The reversal of 1623664008991 is 1998004663261.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1623664008991 - 2³ = 1623664008983 is a prime.

It is a super-2 number, since 2×1623664008991² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1623664008691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 811832004495 + 811832004496.

It is an arithmetic number, because the mean of its divisors is an integer number (811832004496).

Almost surely, 2^{1623664008991} is an apocalyptic number.

1623664008991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1623664008991 is an equidigital number, since it uses as much as digits as its factorization.

1623664008991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3359232, while the sum is 55.

The spelling of 1623664008991 in words is "one trillion, six hundred twenty-three billion, six hundred sixty-four million, eight thousand, nine hundred ninety-one".