1820961810 has 128 divisors (see below), whose sum is σ = 5011787520. Its totient is φ = 476124480.

The previous prime is 1820961761. The next prime is 1820961841. The reversal of 1820961810 is 181690281.

1820961810 is a `hidden beast` number, since 1 + 8 + 20 + 9 + 618 + 10 = 666.

It is a super-2 number, since 2×1820961810² = 6631803826956952200, which contains 22 as substring.

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 63 ways as a sum of consecutive naturals, for example, 1158325 + ... + 1159895.

It is an arithmetic number, because the mean of its divisors is an integer number (39154590).

Almost surely, 2^1820961810 is an apocalyptic number.

1820961810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1820961810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2505893760).

1820961810 is an abundant number, since it is smaller than the sum of its proper divisors (3190825710).

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

1820961810 is an equidigital number, since it uses as much as digits as its factorization.

1820961810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1652 (or 1634 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 36.

The square root of 1820961810 is about 42672.7291135685. The cubic root of 1820961810 is about 1221.1441854732.

The spelling of 1820961810 in words is "one billion, eight hundred twenty million, nine hundred sixty-one thousand, eight hundred ten".