21442212021 has 16 divisors (see below), whose sum is σ = 29292984000. Its totient is φ = 13943268480.

The previous prime is 21442212017. The next prime is 21442212031. The reversal of 21442212021 is 12021224412.

It is not a de Polignac number, because 21442212021 - 2² = 21442212017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442212031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 691966 + ... + 722288.

It is an arithmetic number, because the mean of its divisors is an integer number (1830811500).

Almost surely, 2^21442212021 is an apocalyptic number.

It is an amenable number.

21442212021 is a deficient number, since it is larger than the sum of its proper divisors (7850771979).

21442212021 is a wasteful number, since it uses less digits than its factorization.

21442212021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36116.

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 21442212021 its reverse (12021224412), we get a palindrome (33463436433).

The spelling of 21442212021 in words is "twenty-one billion, four hundred forty-two million, two hundred twelve thousand, twenty-one".