43821987 has 24 divisors (see below), whose sum is σ = 66056640. Its totient is φ = 25626720.

The previous prime is 43821979. The next prime is 43821991. The reversal of 43821987 is 78912834.

It is not a de Polignac number, because 43821987 - 2³ = 43821979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (43821917) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26964 + ... + 28542.

It is an arithmetic number, because the mean of its divisors is an integer number (2752360).

Almost surely, 2^43821987 is an apocalyptic number.

43821987 is a deficient number, since it is larger than the sum of its proper divisors (22234653).

43821987 is a wasteful number, since it uses less digits than its factorization.

43821987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1651 (or 1622 counting only the distinct ones).

The product of its digits is 96768, while the sum is 42.

The square root of 43821987 is about 6619.8177467359. The cubic root of 43821987 is about 352.5580931367.

The spelling of 43821987 in words is "forty-three million, eight hundred twenty-one thousand, nine hundred eighty-seven".