9891218634 has 32 divisors (see below), whose sum is σ = 21591472320. Its totient is φ = 2995862400.

The previous prime is 9891218633. The next prime is 9891218657. The reversal of 9891218634 is 4368121989.

It is not an unprimeable number, because it can be changed into a prime (9891218633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102004 + ... + 173744.

It is an arithmetic number, because the mean of its divisors is an integer number (674733510).

Almost surely, 2^9891218634 is an apocalyptic number.

9891218634 is an abundant number, since it is smaller than the sum of its proper divisors (11700253686).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9891218634 is a wasteful number, since it uses less digits than its factorization.

9891218634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73846.

The product of its digits is 746496, while the sum is 51.

The square root of 9891218634 is about 99454.6058963586. The cubic root of 9891218634 is about 2146.5941123528.

The spelling of 9891218634 in words is "nine billion, eight hundred ninety-one million, two hundred eighteen thousand, six hundred thirty-four".