135220926991 has 4 divisors (see below), whose sum is σ = 135221738184. Its totient is φ = 135220115800.

The previous prime is 135220926989. The next prime is 135220927033. The reversal of 135220926991 is 199629022531.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 199629022531 = 193 ⋅1034347267.

It is a cyclic number.

It is not a de Polignac number, because 135220926991 - 2¹ = 135220926989 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135220926931) 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, 53905 + ... + 522826.

It is an arithmetic number, because the mean of its divisors is an integer number (33805434546).

Almost surely, 2^135220926991 is an apocalyptic number.

135220926991 is a deficient number, since it is larger than the sum of its proper divisors (811193).

135220926991 is an equidigital number, since it uses as much as digits as its factorization.

135220926991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 811192.

The product of its (nonzero) digits is 524880, while the sum is 49.

The spelling of 135220926991 in words is "one hundred thirty-five billion, two hundred twenty million, nine hundred twenty-six thousand, nine hundred ninety-one".