1821807161 has 8 divisors (see below), whose sum is σ = 1947383424. Its totient is φ = 1700094880.

The previous prime is 1821807139. The next prime is 1821807223. The reversal of 1821807161 is 1617081281.

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

It is a cyclic number.

It is not a de Polignac number, because 1821807161 - 2¹⁰ = 1821806137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1821807061) 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, 965021 + ... + 966906.

It is an arithmetic number, because the mean of its divisors is an integer number (243422928).

Almost surely, 2^1821807161 is an apocalyptic number.

It is an amenable number.

1821807161 is a deficient number, since it is larger than the sum of its proper divisors (125576263).

1821807161 is a wasteful number, since it uses less digits than its factorization.

1821807161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1931991.

The product of its (nonzero) digits is 5376, while the sum is 35.

The square root of 1821807161 is about 42682.6330139086. The cubic root of 1821807161 is about 1221.3331214798. Note that the first 3 decimals are identical.

The spelling of 1821807161 in words is "one billion, eight hundred twenty-one million, eight hundred seven thousand, one hundred sixty-one".