21150204 has 12 divisors (see below), whose sum is σ = 49350504. Its totient is φ = 7050064.

The previous prime is 21150203. The next prime is 21150209. The reversal of 21150204 is 40205112.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21150204² = 894662258483232, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21150203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 881247 + ... + 881270.

It is an arithmetic number, because the mean of its divisors is an integer number (4112542).

Almost surely, 2^21150204 is an apocalyptic number.

It is an amenable number.

21150204 is an abundant number, since it is smaller than the sum of its proper divisors (28200300).

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

21150204 is a wasteful number, since it uses less digits than its factorization.

21150204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1762524 (or 1762522 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 21150204 is about 4598.9350941278. The cubic root of 21150204 is about 276.5486356419.

Adding to 21150204 its reverse (40205112), we get a palindrome (61355316).

The spelling of 21150204 in words is "twenty-one million, one hundred fifty thousand, two hundred four".