21990362623 has 2 divisors, whose sum is σ = 21990362624. Its totient is φ = 21990362622.

The previous prime is 21990362599. The next prime is 21990362729. The reversal of 21990362623 is 32626309912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21990362623 - 2³³ = 13400428031 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21990362623.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21990363623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10995181311 + 10995181312.

It is an arithmetic number, because the mean of its divisors is an integer number (10995181312).

Almost surely, 2^21990362623 is an apocalyptic number.

21990362623 is a deficient number, since it is larger than the sum of its proper divisors (1).

21990362623 is an equidigital number, since it uses as much as digits as its factorization.

21990362623 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 43.

The spelling of 21990362623 in words is "twenty-one billion, nine hundred ninety million, three hundred sixty-two thousand, six hundred twenty-three".