21434681187 has 16 divisors (see below), whose sum is σ = 31770907680. Its totient is φ = 14282666496.

The previous prime is 21434681123. The next prime is 21434681189. The reversal of 21434681187 is 78118643412.

21434681187 is a `hidden beast` number, since 2 + 1 + 4 + 3 + 468 + 1 + 187 = 666.

It is not a de Polignac number, because 21434681187 - 2⁶ = 21434681123 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21434681189) 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, 142338 + ... + 251255.

It is an arithmetic number, because the mean of its divisors is an integer number (1985681730).

Almost surely, 2^21434681187 is an apocalyptic number.

21434681187 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21434681187 is a deficient number, since it is larger than the sum of its proper divisors (10336226493).

21434681187 is a wasteful number, since it uses less digits than its factorization.

21434681187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395619 (or 395613 counting only the distinct ones).

The product of its digits is 258048, while the sum is 45.

It can be divided in two parts, 2143 and 4681187, that added together give a triangular number (4683330 = T₃₀₆₀).

The spelling of 21434681187 in words is "twenty-one billion, four hundred thirty-four million, six hundred eighty-one thousand, one hundred eighty-seven".