21122120021 has 8 divisors (see below), whose sum is σ = 21224496384. Its totient is φ = 21019812480.

The previous prime is 21122120011. The next prime is 21122120027. The reversal of 21122120021 is 12002122112.

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 21122120021 - 2³⁰ = 20048378197 is a prime.

It is a super-2 number, since 2×21122120021² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21122119978 and 21122120005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122120027) 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, 662570 + ... + 693716.

It is an arithmetic number, because the mean of its divisors is an integer number (2653062048).

Almost surely, 2^21122120021 is an apocalyptic number.

It is an amenable number.

21122120021 is a deficient number, since it is larger than the sum of its proper divisors (102376363).

21122120021 is a wasteful number, since it uses less digits than its factorization.

21122120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34411.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21122120021 its reverse (12002122112), we get a palindrome (33124242133).

The spelling of 21122120021 in words is "twenty-one billion, one hundred twenty-two million, one hundred twenty thousand, twenty-one".