135621451 has 4 divisors (see below), whose sum is σ = 154995952. Its totient is φ = 116246952.

The previous prime is 135621443. The next prime is 135621457. The reversal of 135621451 is 154126531.

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

It is a cyclic number.

It is not a de Polignac number, because 135621451 - 2³ = 135621443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135621457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9687240 + ... + 9687253.

It is an arithmetic number, because the mean of its divisors is an integer number (38748988).

Almost surely, 2^135621451 is an apocalyptic number.

135621451 is a deficient number, since it is larger than the sum of its proper divisors (19374501).

135621451 is an equidigital number, since it uses as much as digits as its factorization.

135621451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19374500.

The product of its digits is 3600, while the sum is 28.

The square root of 135621451 is about 11645.6623255185. The cubic root of 135621451 is about 513.7787394211.

Adding to 135621451 its reverse (154126531), we get a palindrome (289747982).

The spelling of 135621451 in words is "one hundred thirty-five million, six hundred twenty-one thousand, four hundred fifty-one".