21642127 has 8 divisors (see below), whose sum is σ = 23444064. Its totient is φ = 19859808.

The previous prime is 21642119. The next prime is 21642133. The reversal of 21642127 is 72124612.

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 21642127 - 2³ = 21642119 is a prime.

It is a super-2 number, since 2×21642127² = 936763322168258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21642107) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2563 + ... + 7060.

It is an arithmetic number, because the mean of its divisors is an integer number (2930508).

Almost surely, 2^21642127 is an apocalyptic number.

21642127 is a deficient number, since it is larger than the sum of its proper divisors (1801937).

21642127 is a wasteful number, since it uses less digits than its factorization.

21642127 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9809.

The product of its digits is 1344, while the sum is 25.

The square root of 21642127 is about 4652.1099514091. The cubic root of 21642127 is about 278.6762644896.

Adding to 21642127 its reverse (72124612), we get a palindrome (93766739).

The spelling of 21642127 in words is "twenty-one million, six hundred forty-two thousand, one hundred twenty-seven".