135185621 has 4 divisors (see below), whose sum is σ = 135436044. Its totient is φ = 134935200.

The previous prime is 135185599. The next prime is 135185641. The reversal of 135185621 is 126581531.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 79459396 + 55726225 = 8914^2 + 7465^2 .

It is a cyclic number.

It is not a de Polignac number, because 135185621 - 2¹⁰ = 135184597 is a prime.

It is a super-5 number, since 5×135185621⁵ (a number of 42 digits) contains 55555 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 (135185641) 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, 124400 + ... + 125481.

It is an arithmetic number, because the mean of its divisors is an integer number (33859011).

Almost surely, 2^135185621 is an apocalyptic number.

It is an amenable number.

135185621 is a deficient number, since it is larger than the sum of its proper divisors (250423).

135185621 is an equidigital number, since it uses as much as digits as its factorization.

135185621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250422.

The product of its digits is 7200, while the sum is 32.

The square root of 135185621 is about 11626.9351507609. The cubic root of 135185621 is about 513.2277929519.

The spelling of 135185621 in words is "one hundred thirty-five million, one hundred eighty-five thousand, six hundred twenty-one".