21142773 has 12 divisors (see below), whose sum is σ = 31867680. Its totient is φ = 13482216.

The previous prime is 21142753. The next prime is 21142777. The reversal of 21142773 is 37724112.

It is a happy number.

It is not a de Polignac number, because 21142773 - 2⁵ = 21142741 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21142777) by changing a digit.

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 in 11 ways as a sum of consecutive naturals, for example, 50863 + ... + 51276.

It is an arithmetic number, because the mean of its divisors is an integer number (2655640).

Almost surely, 2^21142773 is an apocalyptic number.

21142773 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21142773 is a deficient number, since it is larger than the sum of its proper divisors (10724907).

21142773 is a wasteful number, since it uses less digits than its factorization.

21142773 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102168 (or 102165 counting only the distinct ones).

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

The square root of 21142773 is about 4598.1271187300. The cubic root of 21142773 is about 276.5162439349.

Adding to 21142773 its reverse (37724112), we get a palindrome (58866885).

The spelling of 21142773 in words is "twenty-one million, one hundred forty-two thousand, seven hundred seventy-three".