20420400023 has 2 divisors, whose sum is σ = 20420400024. Its totient is φ = 20420400022.

The previous prime is 20420399953. The next prime is 20420400037. The reversal of 20420400023 is 32000402402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20420400023 - 2¹⁸ = 20420137879 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 20420399974 and 20420400010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20420400053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10210200011 + 10210200012.

It is an arithmetic number, because the mean of its divisors is an integer number (10210200012).

Almost surely, 2^20420400023 is an apocalyptic number.

20420400023 is a deficient number, since it is larger than the sum of its proper divisors (1).

20420400023 is an equidigital number, since it uses as much as digits as its factorization.

20420400023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 17.

Adding to 20420400023 its reverse (32000402402), we get a palindrome (52420802425).

The spelling of 20420400023 in words is "twenty billion, four hundred twenty million, four hundred thousand, twenty-three".