820081890 has 48 divisors (see below), whose sum is σ = 2145019968. Its totient is φ = 217375008.

The previous prime is 820081861. The next prime is 820081901. The reversal of 820081890 is 98180028.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12252 + ... + 42311.

It is an arithmetic number, because the mean of its divisors is an integer number (44687916).

Almost surely, 2^820081890 is an apocalyptic number.

820081890 is an abundant number, since it is smaller than the sum of its proper divisors (1324938078).

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

820081890 is a wasteful number, since it uses less digits than its factorization.

820081890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54743 (or 54740 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 820081890 is about 28637.0719522789. The cubic root of 820081890 is about 936.0213190958.

The spelling of 820081890 in words is "eight hundred twenty million, eighty-one thousand, eight hundred ninety".