21111431205 has 8 divisors (see below), whose sum is σ = 33778289952. Its totient is φ = 11259429968.

The previous prime is 21111431191. The next prime is 21111431207. The reversal of 21111431205 is 50213411112.

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 21111431205 - 2⁶ = 21111431141 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111431207) 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, 703714359 + ... + 703714388.

It is an arithmetic number, because the mean of its divisors is an integer number (4222286244).

Almost surely, 2^21111431205 is an apocalyptic number.

It is an amenable number.

21111431205 is a deficient number, since it is larger than the sum of its proper divisors (12666858747).

21111431205 is a wasteful number, since it uses less digits than its factorization.

21111431205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1407428755.

The product of its (nonzero) digits is 240, while the sum is 21.

Adding to 21111431205 its reverse (50213411112), we get a palindrome (71324842317).

The spelling of 21111431205 in words is "twenty-one billion, one hundred eleven million, four hundred thirty-one thousand, two hundred five".