21180337 has 8 divisors (see below), whose sum is σ = 21744936. Its totient is φ = 20621952.

The previous prime is 21180331. The next prime is 21180343. The reversal of 21180337 is 73308112.

It is an interprime number because it is at equal distance from previous prime (21180331) and next prime (21180343).

It can be written as a sum of positive squares in 4 ways, for example, as 13512976 + 7667361 = 3676^2 + 2769^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21180337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21180331) 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 7 ways as a sum of consecutive naturals, for example, 5803 + ... + 8719.

It is an arithmetic number, because the mean of its divisors is an integer number (2718117).

Almost surely, 2^21180337 is an apocalyptic number.

It is an amenable number.

21180337 is a deficient number, since it is larger than the sum of its proper divisors (564599).

21180337 is a wasteful number, since it uses less digits than its factorization.

21180337 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3107.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 21180337 is about 4602.2100125918. The cubic root of 21180337 is about 276.6799075936.

Adding to 21180337 its reverse (73308112), we get a palindrome (94488449).

The spelling of 21180337 in words is "twenty-one million, one hundred eighty thousand, three hundred thirty-seven".