2100821000 has 32 divisors (see below), whose sum is σ = 4915923480. Its totient is φ = 840328000.

The previous prime is 2100820999. The next prime is 2100821003. The reversal of 2100821000 is 1280012.

It can be written as a sum of positive squares in 4 ways, for example, as 969575044 + 1131245956 = 31138^2 + 33634^2 .

It is not an unprimeable number, because it can be changed into a prime (2100821003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1049411 + ... + 1051410.

Almost surely, 2^2100821000 is an apocalyptic number.

2100821000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2100821000 is an abundant number, since it is smaller than the sum of its proper divisors (2815102480).

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

2100821000 is a wasteful number, since it uses less digits than its factorization.

2100821000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2100842 (or 2100828 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 2100821000 is about 45834.7139186010. The cubic root of 2100821000 is about 1280.7460250691.

The spelling of 2100821000 in words is "two billion, one hundred million, eight hundred twenty-one thousand".