136156821 has 4 divisors (see below), whose sum is σ = 181542432. Its totient is φ = 90771212.

The previous prime is 136156799. The next prime is 136156843. The reversal of 136156821 is 128651631.

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 an interprime number because it is at equal distance from previous prime (136156799) and next prime (136156843).

It is a cyclic number.

It is not a de Polignac number, because 136156821 - 2⁵ = 136156789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (136156721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22692801 + ... + 22692806.

It is an arithmetic number, because the mean of its divisors is an integer number (45385608).

Almost surely, 2^136156821 is an apocalyptic number.

It is an amenable number.

136156821 is a deficient number, since it is larger than the sum of its proper divisors (45385611).

136156821 is an equidigital number, since it uses as much as digits as its factorization.

136156821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45385610.

The product of its digits is 8640, while the sum is 33.

The square root of 136156821 is about 11668.6254974611. The cubic root of 136156821 is about 514.4539044364.

The spelling of 136156821 in words is "one hundred thirty-six million, one hundred fifty-six thousand, eight hundred twenty-one".