21520041 has 4 divisors (see below), whose sum is σ = 28693392. Its totient is φ = 14346692.

The previous prime is 21520021. The next prime is 21520061. The reversal of 21520041 is 14002512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (21520021) and next prime (21520061).

It is a cyclic number.

It is not a de Polignac number, because 21520041 - 2¹³ = 21511849 is a prime.

It is a super-2 number, since 2×21520041² = 926224329283362, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21520041.

It is not an unprimeable number, because it can be changed into a prime (21520021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3586671 + ... + 3586676.

It is an arithmetic number, because the mean of its divisors is an integer number (7173348).

Almost surely, 2^21520041 is an apocalyptic number.

It is an amenable number.

21520041 is a deficient number, since it is larger than the sum of its proper divisors (7173351).

21520041 is an equidigital number, since it uses as much as digits as its factorization.

21520041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7173350.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 21520041 is about 4638.9698209840. The cubic root of 21520041 is about 278.1512599200.

Adding to 21520041 its reverse (14002512), we get a palindrome (35522553).

The spelling of 21520041 in words is "twenty-one million, five hundred twenty thousand, forty-one".