2121445987 has 4 divisors (see below), whose sum is σ = 2121816256. Its totient is φ = 2121075720.

The previous prime is 2121445981. The next prime is 2121446011. The reversal of 2121445987 is 7895441212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2121445987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2121445981) 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, 176403 + ... + 188044.

It is an arithmetic number, because the mean of its divisors is an integer number (530454064).

Almost surely, 2^2121445987 is an apocalyptic number.

2121445987 is a deficient number, since it is larger than the sum of its proper divisors (370269).

2121445987 is an equidigital number, since it uses as much as digits as its factorization.

2121445987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 370268.

The product of its digits is 161280, while the sum is 43.

The square root of 2121445987 is about 46059.1574716690. The cubic root of 2121445987 is about 1284.9236606226.

The spelling of 2121445987 in words is "two billion, one hundred twenty-one million, four hundred forty-five thousand, nine hundred eighty-seven".