1820420420 has 48 divisors (see below), whose sum is σ = 4705091328. Its totient is φ = 576132480.

The previous prime is 1820420383. The next prime is 1820420429. The reversal of 1820420420 is 240240281.

It is a happy number.

1820420420 is a modest number, since divided by 420420 gives 1820 as remainder.

It is not an unprimeable number, because it can be changed into a prime (1820420429) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 498296 + ... + 501935.

It is an arithmetic number, because the mean of its divisors is an integer number (98022736).

Almost surely, 2^1820420420 is an apocalyptic number.

1820420420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1820420420 is an abundant number, since it is smaller than the sum of its proper divisors (2884670908).

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

1820420420 is a wasteful number, since it uses less digits than its factorization.

1820420420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1000260 (or 1000258 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 23.

The square root of 1820420420 is about 42666.3851292795. The cubic root of 1820420420 is about 1221.0231540534.

The spelling of 1820420420 in words is "one billion, eight hundred twenty million, four hundred twenty thousand, four hundred twenty".