21336157 has 12 divisors (see below), whose sum is σ = 22754844. Its totient is φ = 19997120.

The previous prime is 21336151. The next prime is 21336179. The reversal of 21336157 is 75163312.

It can be written as a sum of positive squares in 2 ways, for example, as 5503716 + 15832441 = 2346^2 + 3979^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21336157 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 (21336151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27657 + ... + 28417.

It is an arithmetic number, because the mean of its divisors is an integer number (1896237).

Almost surely, 2^21336157 is an apocalyptic number.

It is an amenable number.

21336157 is a deficient number, since it is larger than the sum of its proper divisors (1418687).

21336157 is an equidigital number, since it uses as much as digits as its factorization.

21336157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860 (or 837 counting only the distinct ones).

The product of its digits is 3780, while the sum is 28.

The square root of 21336157 is about 4619.1078142862. The cubic root of 21336157 is about 277.3567455824.

Adding to 21336157 its reverse (75163312), we get a palindrome (96499469).

The spelling of 21336157 in words is "twenty-one million, three hundred thirty-six thousand, one hundred fifty-seven".