135639557 has 4 divisors (see below), whose sum is σ = 137664096. Its totient is φ = 133615020.

The previous prime is 135639551. The next prime is 135639563. The reversal of 135639557 is 755936531.

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: 755936531 = 7 ⋅107990933.

It is an interprime number because it is at equal distance from previous prime (135639551) and next prime (135639563).

It is a cyclic number.

It is not a de Polignac number, because 135639557 - 2⁴ = 135639541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135639551) 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, 1012169 + ... + 1012302.

It is an arithmetic number, because the mean of its divisors is an integer number (34416024).

Almost surely, 2^135639557 is an apocalyptic number.

It is an amenable number.

135639557 is a deficient number, since it is larger than the sum of its proper divisors (2024539).

135639557 is an equidigital number, since it uses as much as digits as its factorization.

135639557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2024538.

The product of its digits is 425250, while the sum is 44.

The square root of 135639557 is about 11646.4396705603. The cubic root of 135639557 is about 513.8016022348.

The spelling of 135639557 in words is "one hundred thirty-five million, six hundred thirty-nine thousand, five hundred fifty-seven".