135756421 has 4 divisors (see below), whose sum is σ = 137616172. Its totient is φ = 133896672.

The previous prime is 135756389. The next prime is 135756427. The reversal of 135756421 is 124657531.

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

It can be written as a sum of positive squares in 2 ways, for example, as 102232321 + 33524100 = 10111^2 + 5790^2 .

It is a cyclic number.

It is not a de Polignac number, because 135756421 - 2⁵ = 135756389 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 (135756427) 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, 929766 + ... + 929911.

It is an arithmetic number, because the mean of its divisors is an integer number (34404043).

Almost surely, 2^135756421 is an apocalyptic number.

It is an amenable number.

135756421 is a deficient number, since it is larger than the sum of its proper divisors (1859751).

135756421 is an equidigital number, since it uses as much as digits as its factorization.

135756421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1859750.

The product of its digits is 25200, while the sum is 34.

The square root of 135756421 is about 11651.4557459572. The cubic root of 135756421 is about 513.9491198557.

The spelling of 135756421 in words is "one hundred thirty-five million, seven hundred fifty-six thousand, four hundred twenty-one".