21184040812491 has 48 divisors (see below), whose sum is σ = 32001630336000. Its totient is φ = 13478209394496.

The previous prime is 21184040812433. The next prime is 21184040812523. The reversal of 21184040812491 is 19421804048112.

21184040812491 is a `hidden beast` number, since 2 + 1 + 1 + 8 + 40 + 40 + 81 + 2 + 491 = 666.

It is not a de Polignac number, because 21184040812491 - 2⁶ = 21184040812427 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21184040812391) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 170503210 + ... + 170627408.

It is an arithmetic number, because the mean of its divisors is an integer number (666700632000).

Almost surely, 2^{21184040812491} is an apocalyptic number.

21184040812491 is a deficient number, since it is larger than the sum of its proper divisors (10817589523509).

21184040812491 is a wasteful number, since it uses less digits than its factorization.

21184040812491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126080 (or 126077 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 45.

The spelling of 21184040812491 in words is "twenty-one trillion, one hundred eighty-four billion, forty million, eight hundred twelve thousand, four hundred ninety-one".