420123391 has 2 divisors, whose sum is σ = 420123392. Its totient is φ = 420123390.

The previous prime is 420123367. The next prime is 420123413. The reversal of 420123391 is 193321024.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 420123391 - 2¹⁵ = 420090623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420123331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210061695 + 210061696.

It is an arithmetic number, because the mean of its divisors is an integer number (210061696).

Almost surely, 2^420123391 is an apocalyptic number.

420123391 is a deficient number, since it is larger than the sum of its proper divisors (1).

420123391 is an equidigital number, since it uses as much as digits as its factorization.

420123391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 420123391 is about 20496.9117429919. The cubic root of 420123391 is about 748.9605695929.

The spelling of 420123391 in words is "four hundred twenty million, one hundred twenty-three thousand, three hundred ninety-one".