21112404406 has 4 divisors (see below), whose sum is σ = 31668606612. Its totient is φ = 10556202202.

The previous prime is 21112404367. The next prime is 21112404419. The reversal of 21112404406 is 60440421112.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5278101100 + ... + 5278101103.

It is an arithmetic number, because the mean of its divisors is an integer number (7917151653).

Almost surely, 2^21112404406 is an apocalyptic number.

21112404406 is a deficient number, since it is larger than the sum of its proper divisors (10556202206).

21112404406 is a wasteful number, since it uses less digits than its factorization.

21112404406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10556202205.

The product of its (nonzero) digits is 1536, while the sum is 25.

Adding to 21112404406 its reverse (60440421112), we get a palindrome (81552825518).

The spelling of 21112404406 in words is "twenty-one billion, one hundred twelve million, four hundred four thousand, four hundred six".