21154534211 has 4 divisors (see below), whose sum is σ = 22074296592. Its totient is φ = 20234771832.

The previous prime is 21154534207. The next prime is 21154534229. The reversal of 21154534211 is 11243545112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21154534211 - 2² = 21154534207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21114534211) 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 3 ways as a sum of consecutive naturals, for example, 459881156 + ... + 459881201.

It is an arithmetic number, because the mean of its divisors is an integer number (5518574148).

Almost surely, 2^21154534211 is an apocalyptic number.

21154534211 is a deficient number, since it is larger than the sum of its proper divisors (919762381).

21154534211 is an equidigital number, since it uses as much as digits as its factorization.

21154534211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 919762380.

The product of its digits is 4800, while the sum is 29.

The spelling of 21154534211 in words is "twenty-one billion, one hundred fifty-four million, five hundred thirty-four thousand, two hundred eleven".