21054186 has 12 divisors (see below), whose sum is σ = 45617442. Its totient is φ = 7018056.

The previous prime is 21054181. The next prime is 21054199. The reversal of 21054186 is 68145012.

It can be written as a sum of positive squares in only one way, i.e., 20115225 + 938961 = 4485^2 + 969^2 .

It is not an unprimeable number, because it can be changed into a prime (21054181) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 584821 + ... + 584856.

Almost surely, 2^21054186 is an apocalyptic number.

21054186 is an abundant number, since it is smaller than the sum of its proper divisors (24563256).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21054186 is a wasteful number, since it uses less digits than its factorization.

21054186 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1169685 (or 1169682 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 21054186 is about 4588.4840633917. The cubic root of 21054186 is about 276.1295075896.

Adding to 21054186 its reverse (68145012), we get a palindrome (89199198).

The spelling of 21054186 in words is "twenty-one million, fifty-four thousand, one hundred eighty-six".