36381821 has 4 divisors (see below), whose sum is σ = 41579232. Its totient is φ = 31184412.

The previous prime is 36381809. The next prime is 36381823. The reversal of 36381821 is 12818363.

It is a happy number.

36381821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12818363 = 41 ⋅312643.

It is not a de Polignac number, because 36381821 - 2⁶ = 36381757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (36381823) 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, 2598695 + ... + 2598708.

It is an arithmetic number, because the mean of its divisors is an integer number (10394808).

Almost surely, 2^36381821 is an apocalyptic number.

It is an amenable number.

36381821 is a deficient number, since it is larger than the sum of its proper divisors (5197411).

36381821 is an equidigital number, since it uses as much as digits as its factorization.

36381821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5197410.

The product of its digits is 6912, while the sum is 32.

The square root of 36381821 is about 6031.7344934936. The cubic root of 36381821 is about 331.3559786212.

The spelling of 36381821 in words is "thirty-six million, three hundred eighty-one thousand, eight hundred twenty-one".