420857640 has 256 divisors, whose sum is σ = 1617408000. Its totient is φ = 95351040.

The previous prime is 420857621. The next prime is 420857651. The reversal of 420857640 is 46758024.

420857640 is a `hidden beast` number, since 4 + 2 + 0 + 8 + 5 + 7 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 420857595 and 420857604.

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 63 ways as a sum of consecutive naturals, for example, 1353085 + ... + 1353395.

It is an arithmetic number, because the mean of its divisors is an integer number (6318000).

Almost surely, 2^420857640 is an apocalyptic number.

420857640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 420857640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (808704000).

420857640 is an abundant number, since it is smaller than the sum of its proper divisors (1196550360).

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

420857640 is a wasteful number, since it uses less digits than its factorization.

420857640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517 (or 507 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 420857640 is about 20514.8151344339. The cubic root of 420857640 is about 749.3966347306.

The spelling of 420857640 in words is "four hundred twenty million, eight hundred fifty-seven thousand, six hundred forty".