21142567 has 8 divisors (see below), whose sum is σ = 21438080. Its totient is φ = 20849400.

The previous prime is 21142531. The next prime is 21142613. The reversal of 21142567 is 76524112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21142567 - 2⁷ = 21142439 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21142867) 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 7 ways as a sum of consecutive naturals, for example, 24184 + ... + 25042.

It is an arithmetic number, because the mean of its divisors is an integer number (2679760).

Almost surely, 2^21142567 is an apocalyptic number.

21142567 is a deficient number, since it is larger than the sum of its proper divisors (295513).

21142567 is a wasteful number, since it uses less digits than its factorization.

21142567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1173.

The product of its digits is 3360, while the sum is 28.

The square root of 21142567 is about 4598.1047182508. The cubic root of 21142567 is about 276.5153458734.

Adding to 21142567 its reverse (76524112), we get a palindrome (97666679).

It can be divided in two parts, 211 and 42567, that added together give a triangular number (42778 = T₂₉₂).

The spelling of 21142567 in words is "twenty-one million, one hundred forty-two thousand, five hundred sixty-seven".