21060218 has 4 divisors (see below), whose sum is σ = 31590330. Its totient is φ = 10530108.

The previous prime is 21060211. The next prime is 21060257. The reversal of 21060218 is 81206012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16056049 + 5004169 = 4007^2 + 2237^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21060218.

It is not an unprimeable number, because it can be changed into a prime (21060211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5265053 + ... + 5265056.

Almost surely, 2^21060218 is an apocalyptic number.

21060218 is a deficient number, since it is larger than the sum of its proper divisors (10530112).

21060218 is a wasteful number, since it uses less digits than its factorization.

21060218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10530111.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 21060218 is about 4589.1413140151. The cubic root of 21060218 is about 276.1558753334.

The spelling of 21060218 in words is "twenty-one million, sixty thousand, two hundred eighteen".