135337721 has 4 divisors (see below), whose sum is σ = 135979344. Its totient is φ = 134696100.

The previous prime is 135337687. The next prime is 135337733. The reversal of 135337721 is 127733531.

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 a cyclic number.

It is not a de Polignac number, because 135337721 - 2¹⁰ = 135336697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135337781) 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, 320495 + ... + 320916.

It is an arithmetic number, because the mean of its divisors is an integer number (33994836).

Almost surely, 2^135337721 is an apocalyptic number.

It is an amenable number.

135337721 is a deficient number, since it is larger than the sum of its proper divisors (641623).

135337721 is an equidigital number, since it uses as much as digits as its factorization.

135337721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641622.

The product of its digits is 13230, while the sum is 32.

The square root of 135337721 is about 11633.4741586510. The cubic root of 135337721 is about 513.4202017023.

The spelling of 135337721 in words is "one hundred thirty-five million, three hundred thirty-seven thousand, seven hundred twenty-one".