20423993999 has 2 divisors, whose sum is σ = 20423994000. Its totient is φ = 20423993998.

The previous prime is 20423993957. The next prime is 20423994029. The reversal of 20423993999 is 99939932402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20423993999 - 2¹⁶ = 20423928463 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20423993699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10211996999 + 10211997000.

It is an arithmetic number, because the mean of its divisors is an integer number (10211997000).

Almost surely, 2^20423993999 is an apocalyptic number.

20423993999 is a deficient number, since it is larger than the sum of its proper divisors (1).

20423993999 is an equidigital number, since it uses as much as digits as its factorization.

20423993999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8503056, while the sum is 59.

The spelling of 20423993999 in words is "twenty billion, four hundred twenty-three million, nine hundred ninety-three thousand, nine hundred ninety-nine".