1121821810 has 8 divisors (see below), whose sum is σ = 2019279276. Its totient is φ = 448728720.

The previous prime is 1121821763. The next prime is 1121821817. The reversal of 1121821810 is 181281211.

It can be written as a sum of positive squares in 2 ways, for example, as 1008761121 + 113060689 = 31761^2 + 10633^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×1121821810² = 2516968346783352200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1121821817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56091081 + ... + 56091100.

Almost surely, 2^1121821810 is an apocalyptic number.

1121821810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1121821810 is a deficient number, since it is larger than the sum of its proper divisors (897457466).

1121821810 is a wasteful number, since it uses less digits than its factorization.

1121821810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112182188.

The product of its (nonzero) digits is 256, while the sum is 25.

The square root of 1121821810 is about 33493.6084947561. The cubic root of 1121821810 is about 1039.0615949648.

The spelling of 1121821810 in words is "one billion, one hundred twenty-one million, eight hundred twenty-one thousand, eight hundred ten".