420405390 has 80 divisors (see below), whose sum is σ = 1158086160. Its totient is φ = 109365120.

The previous prime is 420405383. The next prime is 420405443. The reversal of 420405390 is 93504024.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 26881 + ... + 39539.

It is an arithmetic number, because the mean of its divisors is an integer number (14476077).

Almost surely, 2^420405390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 420405390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (579043080).

420405390 is an abundant number, since it is smaller than the sum of its proper divisors (737680770).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

420405390 is a wasteful number, since it uses less digits than its factorization.

420405390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12719 (or 12710 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 420405390 is about 20503.7896497209. The cubic root of 420405390 is about 749.1281067958.

The spelling of 420405390 in words is "four hundred twenty million, four hundred five thousand, three hundred ninety".