21142110021 has 4 divisors (see below), whose sum is σ = 28189480032. Its totient is φ = 14094740012.

The previous prime is 21142110007. The next prime is 21142110053. The reversal of 21142110021 is 12001124112.

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 21142110021 - 2¹³ = 21142101829 is a prime.

It is a super-2 number, since 2×21142110021² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21142110001) 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, 3523685001 + ... + 3523685006.

It is an arithmetic number, because the mean of its divisors is an integer number (7047370008).

Almost surely, 2^21142110021 is an apocalyptic number.

It is an amenable number.

21142110021 is a deficient number, since it is larger than the sum of its proper divisors (7047370011).

21142110021 is an equidigital number, since it uses as much as digits as its factorization.

21142110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7047370010.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21142110021 its reverse (12001124112), we get a palindrome (33143234133).

The spelling of 21142110021 in words is "twenty-one billion, one hundred forty-two million, one hundred ten thousand, twenty-one".