1821871871 has 2 divisors, whose sum is σ = 1821871872. Its totient is φ = 1821871870.

The previous prime is 1821871847. The next prime is 1821871921. The reversal of 1821871871 is 1781781281.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1821871871 - 2¹⁰ = 1821870847 is a prime.

It is a super-2 number, since 2×1821871871² = 6638434228682081282, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1821871801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910935935 + 910935936.

It is an arithmetic number, because the mean of its divisors is an integer number (910935936).

Almost surely, 2^1821871871 is an apocalyptic number.

1821871871 is a deficient number, since it is larger than the sum of its proper divisors (1).

1821871871 is an equidigital number, since it uses as much as digits as its factorization.

1821871871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50176, while the sum is 44.

The square root of 1821871871 is about 42683.3910438241. The cubic root of 1821871871 is about 1221.3475817608.

The spelling of 1821871871 in words is "one billion, eight hundred twenty-one million, eight hundred seventy-one thousand, eight hundred seventy-one".