21001411 has 2 divisors, whose sum is σ = 21001412. Its totient is φ = 21001410.

The previous prime is 21001399. The next prime is 21001417. The reversal of 21001411 is 11410012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21001411 - 2¹⁹ = 20477123 is a prime.

It is not a weakly prime, because it can be changed into another prime (21001417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500705 + 10500706.

It is an arithmetic number, because the mean of its divisors is an integer number (10500706).

Almost surely, 2^21001411 is an apocalyptic number.

21001411 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001411 is an equidigital number, since it uses as much as digits as its factorization.

21001411 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 21001411 is about 4582.7296450914. The cubic root of 21001411 is about 275.8985966140.

Adding to 21001411 its reverse (11410012), we get a palindrome (32411423).

It can be divided in two parts, 21001 and 411, that added together give a palindrome (21412).

The spelling of 21001411 in words is "twenty-one million, one thousand, four hundred eleven".