135766021 has 4 divisors (see below), whose sum is σ = 138067200. Its totient is φ = 133464844.

The previous prime is 135766013. The next prime is 135766067. The reversal of 135766021 is 120667531.

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 not a de Polignac number, because 135766021 - 2³ = 135766013 is a prime.

It is a Smith number, since the sum of its digits (31) 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 (135766121) 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, 1150501 + ... + 1150618.

It is an arithmetic number, because the mean of its divisors is an integer number (34516800).

Almost surely, 2^135766021 is an apocalyptic number.

It is an amenable number.

135766021 is a deficient number, since it is larger than the sum of its proper divisors (2301179).

135766021 is an equidigital number, since it uses as much as digits as its factorization.

135766021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2301178.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 135766021 is about 11651.8677043640. The cubic root of 135766021 is about 513.9612341882.

The spelling of 135766021 in words is "one hundred thirty-five million, seven hundred sixty-six thousand, twenty-one".