1820545820 has 12 divisors (see below), whose sum is σ = 3823146264. Its totient is φ = 728218320.

The previous prime is 1820545807. The next prime is 1820545871. The reversal of 1820545820 is 285450281.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45513626 + ... + 45513665.

It is an arithmetic number, because the mean of its divisors is an integer number (318595522).

Almost surely, 2^1820545820 is an apocalyptic number.

1820545820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1820545820 is an abundant number, since it is smaller than the sum of its proper divisors (2002600444).

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

1820545820 is a wasteful number, since it uses less digits than its factorization.

1820545820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91027300 (or 91027298 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 35.

The square root of 1820545820 is about 42667.8546449198. The cubic root of 1820545820 is about 1221.0511902121.

The spelling of 1820545820 in words is "one billion, eight hundred twenty million, five hundred forty-five thousand, eight hundred twenty".