1820881356 has 192 divisors, whose sum is σ = 5356108800. Its totient is φ = 479431680.

The previous prime is 1820881291. The next prime is 1820881357. The reversal of 1820881356 is 6531880281.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (1820881357) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3708271 + ... + 3708761.

It is an arithmetic number, because the mean of its divisors is an integer number (27896400).

Almost surely, 2^1820881356 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1820881356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2678054400).

1820881356 is an abundant number, since it is smaller than the sum of its proper divisors (3535227444).

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

1820881356 is a wasteful number, since it uses less digits than its factorization.

1820881356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589 (or 573 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 42.

The square root of 1820881356 is about 42671.7864167883. The cubic root of 1820881356 is about 1221.1262009516.

The spelling of 1820881356 in words is "one billion, eight hundred twenty million, eight hundred eighty-one thousand, three hundred fifty-six".