21518083 has 2 divisors, whose sum is σ = 21518084. Its totient is φ = 21518082.

The previous prime is 21518059. The next prime is 21518093. The reversal of 21518083 is 38081512.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21518083 is a prime.

It is a super-3 number, since 3×21518083³ (a number of 23 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21518033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10759041 + 10759042.

It is an arithmetic number, because the mean of its divisors is an integer number (10759042).

Almost surely, 2^21518083 is an apocalyptic number.

21518083 is a deficient number, since it is larger than the sum of its proper divisors (1).

21518083 is an equidigital number, since it uses as much as digits as its factorization.

21518083 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 21518083 is about 4638.7587779491. The cubic root of 21518083 is about 278.1428238041.

Adding to 21518083 its reverse (38081512), we get a palindrome (59599595).

The spelling of 21518083 in words is "twenty-one million, five hundred eighteen thousand, eighty-three".