21534143 has 8 divisors (see below), whose sum is σ = 22120560. Its totient is φ = 20950720.

The previous prime is 21534089. The next prime is 21534151. The reversal of 21534143 is 34143512.

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 21534143 - 2⁸ = 21533887 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 (21534743) 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, 26621 + ... + 27417.

It is an arithmetic number, because the mean of its divisors is an integer number (2765070).

Almost surely, 2^21534143 is an apocalyptic number.

21534143 is a deficient number, since it is larger than the sum of its proper divisors (586417).

21534143 is an equidigital number, since it uses as much as digits as its factorization.

21534143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1497.

The product of its digits is 1440, while the sum is 23.

The square root of 21534143 is about 4640.4895215914. The cubic root of 21534143 is about 278.2120038034.

Adding to 21534143 its reverse (34143512), we get a palindrome (55677655).

The spelling of 21534143 in words is "twenty-one million, five hundred thirty-four thousand, one hundred forty-three".