21134403421 has 4 divisors (see below), whose sum is σ = 21136257952. Its totient is φ = 21132548892.

The previous prime is 21134403413. The next prime is 21134403439. The reversal of 21134403421 is 12430443112.

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 21134403421 - 2³ = 21134403413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21134473421) 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, 910065 + ... + 932998.

It is an arithmetic number, because the mean of its divisors is an integer number (5284064488).

Almost surely, 2^21134403421 is an apocalyptic number.

It is an amenable number.

21134403421 is a deficient number, since it is larger than the sum of its proper divisors (1854531).

21134403421 is a wasteful number, since it uses less digits than its factorization.

21134403421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1854530.

The product of its (nonzero) digits is 2304, while the sum is 25.

Adding to 21134403421 its reverse (12430443112), we get a palindrome (33564846533).

The spelling of 21134403421 in words is "twenty-one billion, one hundred thirty-four million, four hundred three thousand, four hundred twenty-one".