20899621729423 has 2 divisors, whose sum is σ = 20899621729424. Its totient is φ = 20899621729422.

The previous prime is 20899621729351. The next prime is 20899621729439. The reversal of 20899621729423 is 32492712699802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20899621729423 - 2²¹ = 20899619632271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20899621129423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10449810864711 + 10449810864712.

It is an arithmetic number, because the mean of its divisors is an integer number (10449810864712).

Almost surely, 2^{20899621729423} is an apocalyptic number.

20899621729423 is a deficient number, since it is larger than the sum of its proper divisors (1).

20899621729423 is an equidigital number, since it uses as much as digits as its factorization.

20899621729423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 47029248, while the sum is 64.

The spelling of 20899621729423 in words is "twenty trillion, eight hundred ninety-nine billion, six hundred twenty-one million, seven hundred twenty-nine thousand, four hundred twenty-three".