21508041 has 16 divisors (see below), whose sum is σ = 29582784. Its totient is φ = 13891584.

The previous prime is 21508031. The next prime is 21508061. The reversal of 21508041 is 14080512.

It is not a de Polignac number, because 21508041 - 2⁶ = 21507977 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21507999 and 21508017.

It is not an unprimeable number, because it can be changed into a prime (21508031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17065 + ... + 18281.

It is an arithmetic number, because the mean of its divisors is an integer number (1848924).

Almost surely, 2^21508041 is an apocalyptic number.

It is an amenable number.

21508041 is a deficient number, since it is larger than the sum of its proper divisors (8074743).

21508041 is a wasteful number, since it uses less digits than its factorization.

21508041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1400.

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 21508041 is about 4637.6762500200. The cubic root of 21508041 is about 278.0995494281.

Adding to 21508041 its reverse (14080512), we get a palindrome (35588553).

The spelling of 21508041 in words is "twenty-one million, five hundred eight thousand, forty-one".