21111100291 has 8 divisors (see below), whose sum is σ = 21511617120. Its totient is φ = 20710664832.

The previous prime is 21111100289. The next prime is 21111100343. The reversal of 21111100291 is 19200111112.

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

It is a cyclic number.

It is not a de Polignac number, because 21111100291 - 2¹ = 21111100289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111170291) 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, 863451 + ... + 887563.

It is an arithmetic number, because the mean of its divisors is an integer number (2688952140).

Almost surely, 2^21111100291 is an apocalyptic number.

21111100291 is a deficient number, since it is larger than the sum of its proper divisors (400516829).

21111100291 is a wasteful number, since it uses less digits than its factorization.

21111100291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40685.

The product of its (nonzero) digits is 36, while the sum is 19.

The spelling of 21111100291 in words is "twenty-one billion, one hundred eleven million, one hundred thousand, two hundred ninety-one".