21150172 has 6 divisors (see below), whose sum is σ = 37012808. Its totient is φ = 10575084.

The previous prime is 21150163. The next prime is 21150187. The reversal of 21150172 is 27105112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2643768 + ... + 2643775.

Almost surely, 2^21150172 is an apocalyptic number.

It is an amenable number.

21150172 is a deficient number, since it is larger than the sum of its proper divisors (15862636).

21150172 is a wasteful number, since it uses less digits than its factorization.

21150172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5287547 (or 5287545 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 19.

The square root of 21150172 is about 4598.9316150602. The cubic root of 21150172 is about 276.5484961703.

Adding to 21150172 its reverse (27105112), we get a palindrome (48255284).

The spelling of 21150172 in words is "twenty-one million, one hundred fifty thousand, one hundred seventy-two".