134640021 has 4 divisors (see below), whose sum is σ = 179520032. Its totient is φ = 89760012.

The previous prime is 134640019. The next prime is 134640029. The reversal of 134640021 is 120046431.

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 not a de Polignac number, because 134640021 - 2¹ = 134640019 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 134640021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (134640029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22440001 + ... + 22440006.

It is an arithmetic number, because the mean of its divisors is an integer number (44880008).

Almost surely, 2^134640021 is an apocalyptic number.

It is an amenable number.

134640021 is a deficient number, since it is larger than the sum of its proper divisors (44880011).

134640021 is an equidigital number, since it uses as much as digits as its factorization.

134640021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44880010.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 134640021 is about 11603.4486683917. The cubic root of 134640021 is about 512.5364111351.

Adding to 134640021 its reverse (120046431), we get a palindrome (254686452).

The spelling of 134640021 in words is "one hundred thirty-four million, six hundred forty thousand, twenty-one".