135540420121 has 4 divisors (see below), whose sum is σ = 135608090832. Its totient is φ = 135472749412.

The previous prime is 135540420109. The next prime is 135540420131. The reversal of 135540420121 is 121024045531.

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 a de Polignac number, because none of the positive numbers 2^k-135540420121 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 135540420121.

It is not an unprimeable number, because it can be changed into a prime (135540420131) 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, 33832351 + ... + 33836356.

It is an arithmetic number, because the mean of its divisors is an integer number (33902022708).

Almost surely, 2^135540420121 is an apocalyptic number.

It is an amenable number.

135540420121 is a deficient number, since it is larger than the sum of its proper divisors (67670711).

135540420121 is an equidigital number, since it uses as much as digits as its factorization.

135540420121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67670710.

The product of its (nonzero) digits is 4800, while the sum is 28.

Adding to 135540420121 its reverse (121024045531), we get a palindrome (256564465652).

The spelling of 135540420121 in words is "one hundred thirty-five billion, five hundred forty million, four hundred twenty thousand, one hundred twenty-one".