1021112820 has 576 divisors, whose sum is σ = 4270855680. Its totient is φ = 191102976.

The previous prime is 1021112789. The next prime is 1021112821. The reversal of 1021112820 is 282111201.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1021112793 and 1021112802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021112821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 5290644 + ... + 5290836.

It is an arithmetic number, because the mean of its divisors is an integer number (7414680).

Almost surely, 2^1021112820 is an apocalyptic number.

1021112820 is a gapful number since it is divisible by the number (10) 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 1021112820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2135427840).

1021112820 is an abundant number, since it is smaller than the sum of its proper divisors (3249742860).

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

1021112820 is a wasteful number, since it uses less digits than its factorization.

1021112820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264 (or 259 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

The square root of 1021112820 is about 31954.8559690073. The cubic root of 1021112820 is about 1006.9886516368.

The spelling of 1021112820 in words is "one billion, twenty-one million, one hundred twelve thousand, eight hundred twenty".