420505091 has 2 divisors, whose sum is σ = 420505092. Its totient is φ = 420505090.

The previous prime is 420505073. The next prime is 420505121. The reversal of 420505091 is 190505024.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-420505091 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 420505091.

It is not a weakly prime, because it can be changed into another prime (420505051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210252545 + 210252546.

It is an arithmetic number, because the mean of its divisors is an integer number (210252546).

Almost surely, 2^420505091 is an apocalyptic number.

420505091 is a deficient number, since it is larger than the sum of its proper divisors (1).

420505091 is an equidigital number, since it uses as much as digits as its factorization.

420505091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 420505091 is about 20506.2207878487. The cubic root of 420505091 is about 749.1873217977.

The spelling of 420505091 in words is "four hundred twenty million, five hundred five thousand, ninety-one".