21420140134 has 4 divisors (see below), whose sum is σ = 32130210204. Its totient is φ = 10710070066.

The previous prime is 21420140129. The next prime is 21420140171. The reversal of 21420140134 is 43104102412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5355035032 + ... + 5355035035.

It is an arithmetic number, because the mean of its divisors is an integer number (8032552551).

Almost surely, 2^21420140134 is an apocalyptic number.

21420140134 is a deficient number, since it is larger than the sum of its proper divisors (10710070070).

21420140134 is a wasteful number, since it uses less digits than its factorization.

21420140134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10710070069.

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21420140134 its reverse (43104102412), we get a palindrome (64524242546).

The spelling of 21420140134 in words is "twenty-one billion, four hundred twenty million, one hundred forty thousand, one hundred thirty-four".