21539141 has 32 divisors (see below), whose sum is σ = 26342400. Its totient is φ = 17418240.

The previous prime is 21539137. The next prime is 21539149. The reversal of 21539141 is 14193512.

It is a cyclic number.

It is not a de Polignac number, because 21539141 - 2² = 21539137 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21539141.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21539149) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 222005 + ... + 222101.

It is an arithmetic number, because the mean of its divisors is an integer number (823200).

Almost surely, 2^21539141 is an apocalyptic number.

It is an amenable number.

21539141 is a deficient number, since it is larger than the sum of its proper divisors (4803259).

21539141 is a wasteful number, since it uses less digits than its factorization.

21539141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189.

The product of its digits is 1080, while the sum is 26.

The square root of 21539141 is about 4641.0280111200. The cubic root of 21539141 is about 278.2335261526.

The spelling of 21539141 in words is "twenty-one million, five hundred thirty-nine thousand, one hundred forty-one".