21113421155 has 8 divisors (see below), whose sum is σ = 25560319392. Its totient is φ = 16741260928.

The previous prime is 21113421107. The next prime is 21113421157. The reversal of 21113421155 is 55112431112.

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 21113421155 - 2⁸ = 21113420899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21113421157) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18683879 + ... + 18685008.

It is an arithmetic number, because the mean of its divisors is an integer number (3195039924).

Almost surely, 2^21113421155 is an apocalyptic number.

21113421155 is a deficient number, since it is larger than the sum of its proper divisors (4446898237).

21113421155 is a wasteful number, since it uses less digits than its factorization.

21113421155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37369005.

The product of its digits is 1200, while the sum is 26.

Adding to 21113421155 its reverse (55112431112), we get a palindrome (76225852267).

The spelling of 21113421155 in words is "twenty-one billion, one hundred thirteen million, four hundred twenty-one thousand, one hundred fifty-five".