21261408113 has 4 divisors (see below), whose sum is σ = 23194263408. Its totient is φ = 19328552820.

The previous prime is 21261408043. The next prime is 21261408121. The reversal of 21261408113 is 31180416212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21261408113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21261408193) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 966427631 + ... + 966427652.

It is an arithmetic number, because the mean of its divisors is an integer number (5798565852).

Almost surely, 2^21261408113 is an apocalyptic number.

It is an amenable number.

21261408113 is a deficient number, since it is larger than the sum of its proper divisors (1932855295).

21261408113 is a wasteful number, since it uses less digits than its factorization.

21261408113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1932855294.

The product of its (nonzero) digits is 2304, while the sum is 29.

The spelling of 21261408113 in words is "twenty-one billion, two hundred sixty-one million, four hundred eight thousand, one hundred thirteen".