1811956420 has 12 divisors (see below), whose sum is σ = 3805108524. Its totient is φ = 724782560.

The previous prime is 1811956313. The next prime is 1811956427. The reversal of 1811956420 is 246591181.

It can be written as a sum of positive squares in 2 ways, for example, as 415588996 + 1396367424 = 20386^2 + 37368^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1811956420.

It is not an unprimeable number, because it can be changed into a prime (1811956427) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45298891 + ... + 45298930.

It is an arithmetic number, because the mean of its divisors is an integer number (317092377).

Almost surely, 2^1811956420 is an apocalyptic number.

1811956420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1811956420 is an abundant number, since it is smaller than the sum of its proper divisors (1993152104).

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

1811956420 is a wasteful number, since it uses less digits than its factorization.

1811956420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90597830 (or 90597828 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 1811956420 is about 42567.0814127537. The cubic root of 1811956420 is about 1219.1278412265.

The spelling of 1811956420 in words is "one billion, eight hundred eleven million, nine hundred fifty-six thousand, four hundred twenty".