21020650423 has 2 divisors, whose sum is σ = 21020650424. Its totient is φ = 21020650422.

The previous prime is 21020650411. The next prime is 21020650451. The reversal of 21020650423 is 32405602012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020650423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020650463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510325211 + 10510325212.

It is an arithmetic number, because the mean of its divisors is an integer number (10510325212).

Almost surely, 2^21020650423 is an apocalyptic number.

21020650423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020650423 is an equidigital number, since it uses as much as digits as its factorization.

21020650423 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 25.

The spelling of 21020650423 in words is "twenty-one billion, twenty million, six hundred fifty thousand, four hundred twenty-three".