3985622891 has 4 divisors (see below), whose sum is σ = 3991510752. Its totient is φ = 3979735032.

The previous prime is 3985622857. The next prime is 3985622897. The reversal of 3985622891 is 1982265893.

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 3985622891 - 2²⁶ = 3918514027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3985622897) 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, 2942915 + ... + 2944268.

It is an arithmetic number, because the mean of its divisors is an integer number (997877688).

Almost surely, 2^3985622891 is an apocalyptic number.

3985622891 is a deficient number, since it is larger than the sum of its proper divisors (5887861).

3985622891 is an equidigital number, since it uses as much as digits as its factorization.

3985622891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5887860.

The product of its digits is 1866240, while the sum is 53.

The square root of 3985622891 is about 63131.7898605766. The cubic root of 3985622891 is about 1585.4969156489.

The spelling of 3985622891 in words is "three billion, nine hundred eighty-five million, six hundred twenty-two thousand, eight hundred ninety-one".