21186136 has 8 divisors (see below), whose sum is σ = 39724020. Its totient is φ = 10593064.

The previous prime is 21186127. The next prime is 21186149. The reversal of 21186136 is 63168112.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×21186136² = 897704717220992, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1324126 + ... + 1324141.

Almost surely, 2^21186136 is an apocalyptic number.

It is an amenable number.

21186136 is a deficient number, since it is larger than the sum of its proper divisors (18537884).

21186136 is a wasteful number, since it uses less digits than its factorization.

21186136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2648273 (or 2648269 counting only the distinct ones).

The product of its digits is 1728, while the sum is 28.

The square root of 21186136 is about 4602.8399928740. The cubic root of 21186136 is about 276.7051561748.

The spelling of 21186136 in words is "twenty-one million, one hundred eighty-six thousand, one hundred thirty-six".