981213851 has 4 divisors (see below), whose sum is σ = 986635104. Its totient is φ = 975792600.

The previous prime is 981213847. The next prime is 981213859. The reversal of 981213851 is 158312189.

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 981213851 - 2² = 981213847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (981213859) 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, 2710355 + ... + 2710716.

It is an arithmetic number, because the mean of its divisors is an integer number (246658776).

Almost surely, 2^981213851 is an apocalyptic number.

981213851 is a deficient number, since it is larger than the sum of its proper divisors (5421253).

981213851 is a wasteful number, since it uses less digits than its factorization.

981213851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5421252.

The product of its digits is 17280, while the sum is 38.

The square root of 981213851 is about 31324.3332091842. Note that the first 3 decimals coincide. The cubic root of 981213851 is about 993.6983226110.

It can be divided in two parts, 9812138 and 51, that added together give a palindrome (9812189).

The spelling of 981213851 in words is "nine hundred eighty-one million, two hundred thirteen thousand, eight hundred fifty-one".