21743172 has 36 divisors (see below), whose sum is σ = 59959536. Its totient is φ = 6588720.

The previous prime is 21743131. The next prime is 21743177. The reversal of 21743172 is 27134712.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (21743177) 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 11 ways as a sum of consecutive naturals, for example, 27058 + ... + 27849.

Almost surely, 2^21743172 is an apocalyptic number.

21743172 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21743172 is an abundant number, since it is smaller than the sum of its proper divisors (38216364).

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

21743172 is a wasteful number, since it uses less digits than its factorization.

21743172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54928 (or 54923 counting only the distinct ones).

The product of its digits is 2352, while the sum is 27.

The square root of 21743172 is about 4662.9574306442. The cubic root of 21743172 is about 279.1092954455.

Adding to 21743172 its reverse (27134712), we get a palindrome (48877884).

The spelling of 21743172 in words is "twenty-one million, seven hundred forty-three thousand, one hundred seventy-two".