2181987963 has 10 divisors (see below), whose sum is σ = 3259513004. Its totient is φ = 1454658588.

The previous prime is 2181987959. The next prime is 2181988021. The reversal of 2181987963 is 3697891812.

It is not a de Polignac number, because 2181987963 - 2² = 2181987959 is a prime.

It is a super-2 number, since 2×2181987963² = 9522142941353778738, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2181987953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 13468981 + ... + 13469142.

Almost surely, 2^2181987963 is an apocalyptic number.

2181987963 is a deficient number, since it is larger than the sum of its proper divisors (1077525041).

2181987963 is an equidigital number, since it uses as much as digits as its factorization.

2181987963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26938135 (or 26938126 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 54.

The square root of 2181987963 is about 46711.7540133102. The cubic root of 2181987963 is about 1297.0322762008.

The spelling of 2181987963 in words is "two billion, one hundred eighty-one million, nine hundred eighty-seven thousand, nine hundred sixty-three".