21420140135 has 8 divisors (see below), whose sum is σ = 25741806480. Its totient is φ = 17111019904.

The previous prime is 21420140129. The next prime is 21420140171. The reversal of 21420140135 is 53104102412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21420140135 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21420140135.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3132770 + ... + 3139599.

It is an arithmetic number, because the mean of its divisors is an integer number (3217725810).

Almost surely, 2^21420140135 is an apocalyptic number.

21420140135 is a deficient number, since it is larger than the sum of its proper divisors (4321666345).

21420140135 is an equidigital number, since it uses as much as digits as its factorization.

21420140135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6273057.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 21420140135 its reverse (53104102412), we get a palindrome (74524242547).

The spelling of 21420140135 in words is "twenty-one billion, four hundred twenty million, one hundred forty thousand, one hundred thirty-five".