21899418891 has 8 divisors (see below), whose sum is σ = 33370543104. Its totient is φ = 12513953640.

The previous prime is 21899418883. The next prime is 21899418907. The reversal of 21899418891 is 19881499812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21899418891 - 2³ = 21899418883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21899418811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 521414715 + ... + 521414756.

It is an arithmetic number, because the mean of its divisors is an integer number (4171317888).

Almost surely, 2^21899418891 is an apocalyptic number.

21899418891 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21899418891 is a deficient number, since it is larger than the sum of its proper divisors (11471124213).

21899418891 is a wasteful number, since it uses less digits than its factorization.

21899418891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1042829481.

The product of its digits is 2985984, while the sum is 60.

The spelling of 21899418891 in words is "twenty-one billion, eight hundred ninety-nine million, four hundred eighteen thousand, eight hundred ninety-one".