135144644221 has 4 divisors (see below), whose sum is σ = 136855336000. Its totient is φ = 133433952444.

The previous prime is 135144644179. The next prime is 135144644249. The reversal of 135144644221 is 122446441531.

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, and also an emirpimes, since its reverse is a distinct semiprime: 122446441531 = 11383 ⋅10756957.

It is a cyclic number.

It is not a de Polignac number, because 135144644221 - 2¹⁷ = 135144513149 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 (135144644021) 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, 855345771 + ... + 855345928.

It is an arithmetic number, because the mean of its divisors is an integer number (34213834000).

Almost surely, 2^135144644221 is an apocalyptic number.

It is an amenable number.

135144644221 is a deficient number, since it is larger than the sum of its proper divisors (1710691779).

135144644221 is an equidigital number, since it uses as much as digits as its factorization.

135144644221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1710691778.

The product of its digits is 92160, while the sum is 37.

The spelling of 135144644221 in words is "one hundred thirty-five billion, one hundred forty-four million, six hundred forty-four thousand, two hundred twenty-one".