21002120133 has 4 divisors (see below), whose sum is σ = 28002826848. Its totient is φ = 14001413420.

The previous prime is 21002120129. The next prime is 21002120147. The reversal of 21002120133 is 33102120012.

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 21002120133 - 2² = 21002120129 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002120173) 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, 3500353353 + ... + 3500353358.

It is an arithmetic number, because the mean of its divisors is an integer number (7000706712).

Almost surely, 2^21002120133 is an apocalyptic number.

It is an amenable number.

21002120133 is a deficient number, since it is larger than the sum of its proper divisors (7000706715).

21002120133 is an equidigital number, since it uses as much as digits as its factorization.

21002120133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7000706714.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21002120133 its reverse (33102120012), we get a palindrome (54104240145).

The spelling of 21002120133 in words is "twenty-one billion, two million, one hundred twenty thousand, one hundred thirty-three".