135821144 has 8 divisors (see below), whose sum is σ = 254664660. Its totient is φ = 67910568.

The previous prime is 135821131. The next prime is 135821149. The reversal of 135821144 is 441128531.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135821149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8488814 + ... + 8488829.

Almost surely, 2^135821144 is an apocalyptic number.

It is an amenable number.

135821144 is a deficient number, since it is larger than the sum of its proper divisors (118843516).

135821144 is a wasteful number, since it uses less digits than its factorization.

135821144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16977649 (or 16977645 counting only the distinct ones).

The product of its digits is 3840, while the sum is 29.

The square root of 135821144 is about 11654.2328790873. The cubic root of 135821144 is about 514.0307833815.

Adding to 135821144 its reverse (441128531), we get a palindrome (576949675).

The spelling of 135821144 in words is "one hundred thirty-five million, eight hundred twenty-one thousand, one hundred forty-four".