1021871808 has 84 divisors (see below), whose sum is σ = 3008025480. Its totient is φ = 340180992.

The previous prime is 1021871803. The next prime is 1021871821. The reversal of 1021871808 is 8081781201.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (1021871803) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 1328448 + ... + 1329216.

Almost surely, 2^1021871808 is an apocalyptic number.

1021871808 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1021871808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1504012740).

1021871808 is an abundant number, since it is smaller than the sum of its proper divisors (1986153672).

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

1021871808 is an frugal number, since it uses more digits than its factorization.

1021871808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1559 (or 774 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 36.

The square root of 1021871808 is about 31966.7297044912. The cubic root of 1021871808 is about 1007.2380863715.

The spelling of 1021871808 in words is "one billion, twenty-one million, eight hundred seventy-one thousand, eight hundred eight".