209999028623 has 2 divisors, whose sum is σ = 209999028624. Its totient is φ = 209999028622.

The previous prime is 209999028599. The next prime is 209999028641. The reversal of 209999028623 is 326820999902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 209999028623 - 2¹⁴ = 209999012239 is a prime.

It is a super-2 number, since 2×209999028623² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209999028653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104999514311 + 104999514312.

It is an arithmetic number, because the mean of its divisors is an integer number (104999514312).

Almost surely, 2^209999028623 is an apocalyptic number.

209999028623 is a deficient number, since it is larger than the sum of its proper divisors (1).

209999028623 is an equidigital number, since it uses as much as digits as its factorization.

209999028623 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7558272, while the sum is 59.

The spelling of 209999028623 in words is "two hundred nine billion, nine hundred ninety-nine million, twenty-eight thousand, six hundred twenty-three".