21419172 has 18 divisors (see below), whose sum is σ = 54142998. Its totient is φ = 7139712.

The previous prime is 21419143. The next prime is 21419173. The reversal of 21419172 is 27191412.

It can be written as a sum of positive squares in only one way, i.e., 20304036 + 1115136 = 4506^2 + 1056^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (21419173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 297453 + ... + 297524.

Almost surely, 2^21419172 is an apocalyptic number.

It is an amenable number.

21419172 is an abundant number, since it is smaller than the sum of its proper divisors (32723826).

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

21419172 is a wasteful number, since it uses less digits than its factorization.

21419172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 594987 (or 594982 counting only the distinct ones).

The product of its digits is 1008, while the sum is 27.

The square root of 21419172 is about 4628.0851331841. The cubic root of 21419172 is about 277.7159944844.

The spelling of 21419172 in words is "twenty-one million, four hundred nineteen thousand, one hundred seventy-two".