21134212021 has 12 divisors (see below), whose sum is σ = 22906698528. Its totient is φ = 19489985424.

The previous prime is 21134211991. The next prime is 21134212081. The reversal of 21134212021 is 12021243112.

It is not a de Polignac number, because 21134212021 - 2²³ = 21125823413 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21134212021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21134212081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 120826 + ... + 238468.

It is an arithmetic number, because the mean of its divisors is an integer number (1908891544).

Almost surely, 2^21134212021 is an apocalyptic number.

It is an amenable number.

21134212021 is a deficient number, since it is larger than the sum of its proper divisors (1772486507).

21134212021 is a wasteful number, since it uses less digits than its factorization.

21134212021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118732 (or 118719 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 21134212021 its reverse (12021243112), we get a palindrome (33155455133).

The spelling of 21134212021 in words is "twenty-one billion, one hundred thirty-four million, two hundred twelve thousand, twenty-one".