21518485 has 8 divisors (see below), whose sum is σ = 25967520. Its totient is φ = 17117904.

The previous prime is 21518479. The next prime is 21518489. The reversal of 21518485 is 58481512.

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

It is a cyclic number.

It is not a de Polignac number, because 21518485 - 2⁹ = 21517973 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21518485.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21518489) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11127 + ... + 12916.

It is an arithmetic number, because the mean of its divisors is an integer number (3245940).

Almost surely, 2^21518485 is an apocalyptic number.

It is an amenable number.

21518485 is a deficient number, since it is larger than the sum of its proper divisors (4449035).

21518485 is a wasteful number, since it uses less digits than its factorization.

21518485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24227.

The product of its digits is 12800, while the sum is 34.

The square root of 21518485 is about 4638.8021083034. The cubic root of 21518485 is about 278.1445558778.

Adding to 21518485 its reverse (58481512), we get a palindrome (79999997).

The spelling of 21518485 in words is "twenty-one million, five hundred eighteen thousand, four hundred eighty-five".