4391987 has 4 divisors (see below), whose sum is σ = 4533696. Its totient is φ = 4250280.

The previous prime is 4391969. The next prime is 4391993. The reversal of 4391987 is 7891934.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 4391987 - 2⁶ = 4391923 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4391957) 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, 70808 + ... + 70869.

It is an arithmetic number, because the mean of its divisors is an integer number (1133424).

Almost surely, 2^4391987 is an apocalyptic number.

4391987 is a deficient number, since it is larger than the sum of its proper divisors (141709).

4391987 is a wasteful number, since it uses less digits than its factorization.

4391987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141708.

The product of its digits is 54432, while the sum is 41.

The square root of 4391987 is about 2095.7068020122. The cubic root of 4391987 is about 163.7647206237.

The spelling of 4391987 in words is "four million, three hundred ninety-one thousand, nine hundred eighty-seven".