21182288491 has 64 divisors (see below), whose sum is σ = 28168197120. Its totient is φ = 15463042560.

The previous prime is 21182288467. The next prime is 21182288521. The reversal of 21182288491 is 19488228112.

It is a de Polignac number, because none of the positive numbers 2^k-21182288491 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21182288401) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11284245 + ... + 11286121.

It is an arithmetic number, because the mean of its divisors is an integer number (440128080).

Almost surely, 2^21182288491 is an apocalyptic number.

21182288491 is a deficient number, since it is larger than the sum of its proper divisors (6985908629).

21182288491 is a wasteful number, since it uses less digits than its factorization.

21182288491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2084.

The product of its digits is 147456, while the sum is 46.

The spelling of 21182288491 in words is "twenty-one billion, one hundred eighty-two million, two hundred eighty-eight thousand, four hundred ninety-one".