135939631 has 4 divisors (see below), whose sum is σ = 136538712. Its totient is φ = 135340552.

The previous prime is 135939613. The next prime is 135939673. The reversal of 135939631 is 136939531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 136939531 = 59 ⋅2321009.

It is a cyclic number.

It is not a de Polignac number, because 135939631 - 2⁹ = 135939119 is a prime.

It is a super-2 number, since 2×135939631² = 36959166552832322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135939731) 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, 299200 + ... + 299653.

It is an arithmetic number, because the mean of its divisors is an integer number (34134678).

Almost surely, 2^135939631 is an apocalyptic number.

135939631 is a deficient number, since it is larger than the sum of its proper divisors (599081).

135939631 is an equidigital number, since it uses as much as digits as its factorization.

135939631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 599080.

The product of its digits is 65610, while the sum is 40.

The square root of 135939631 is about 11659.3152028753. The cubic root of 135939631 is about 514.1802158416.

The spelling of 135939631 in words is "one hundred thirty-five million, nine hundred thirty-nine thousand, six hundred thirty-one".