21706991133 has 4 divisors (see below), whose sum is σ = 28942654848. Its totient is φ = 14471327420.

The previous prime is 21706991029. The next prime is 21706991143. The reversal of 21706991133 is 33119960712.

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 not a de Polignac number, because 21706991133 - 2⁹ = 21706990621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21706991143) 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, 3617831853 + ... + 3617831858.

It is an arithmetic number, because the mean of its divisors is an integer number (7235663712).

Almost surely, 2^21706991133 is an apocalyptic number.

It is an amenable number.

21706991133 is a deficient number, since it is larger than the sum of its proper divisors (7235663715).

21706991133 is an equidigital number, since it uses as much as digits as its factorization.

21706991133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7235663714.

The product of its (nonzero) digits is 61236, while the sum is 42.

The spelling of 21706991133 in words is "twenty-one billion, seven hundred six million, nine hundred ninety-one thousand, one hundred thirty-three".