4891212121985 has 32 divisors (see below), whose sum is σ = 6947170364160. Its totient is φ = 3234626664192.

The previous prime is 4891212121981. The next prime is 4891212122011. The reversal of 4891212121985 is 5891212121984.

It is not a de Polignac number, because 4891212121985 - 2² = 4891212121981 is a prime.

It is not an unprimeable number, because it can be changed into a prime (4891212121981) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1857239 + ... + 3637548.

It is an arithmetic number, because the mean of its divisors is an integer number (217099073880).

Almost surely, 2^{4891212121985} is an apocalyptic number.

It is an amenable number.

4891212121985 is a deficient number, since it is larger than the sum of its proper divisors (2055958242175).

4891212121985 is a wasteful number, since it uses less digits than its factorization.

4891212121985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5495705.

The product of its digits is 829440, while the sum is 53.

Subtracting 4891212121985 from its reverse (5891212121984), we obtain a palindrome (999999999999).

The spelling of 4891212121985 in words is "four trillion, eight hundred ninety-one billion, two hundred twelve million, one hundred twenty-one thousand, nine hundred eighty-five".