1881684491 has 6 divisors (see below), whose sum is σ = 1998883140. Its totient is φ = 1770996896.

The previous prime is 1881684403. The next prime is 1881684509. The reversal of 1881684491 is 1944861881.

It is not a de Polignac number, because 1881684491 - 2¹⁰ = 1881683467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1881684391) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3255221 + ... + 3255798.

It is an arithmetic number, because the mean of its divisors is an integer number (333147190).

Almost surely, 2^1881684491 is an apocalyptic number.

1881684491 is a deficient number, since it is larger than the sum of its proper divisors (117198649).

1881684491 is an equidigital number, since it uses as much as digits as its factorization.

1881684491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6511053 (or 6511036 counting only the distinct ones).

The product of its digits is 442368, while the sum is 50.

The square root of 1881684491 is about 43378.3873720543. The cubic root of 1881684491 is about 1234.5696656689.

The spelling of 1881684491 in words is "one billion, eight hundred eighty-one million, six hundred eighty-four thousand, four hundred ninety-one".