21441913 has 4 divisors (see below), whose sum is σ = 22703220. Its totient is φ = 20180608.

The previous prime is 21441887. The next prime is 21441919. The reversal of 21441913 is 31914412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19333609 + 2108304 = 4397^2 + 1452^2 .

It is a cyclic number.

It is not a de Polignac number, because 21441913 - 2⁵ = 21441881 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (21441919) 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, 630628 + ... + 630661.

It is an arithmetic number, because the mean of its divisors is an integer number (5675805).

Almost surely, 2^21441913 is an apocalyptic number.

It is an amenable number.

21441913 is a deficient number, since it is larger than the sum of its proper divisors (1261307).

21441913 is a wasteful number, since it uses less digits than its factorization.

21441913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1261306.

The product of its digits is 864, while the sum is 25.

The square root of 21441913 is about 4630.5413290457. The cubic root of 21441913 is about 277.8142445576.

The spelling of 21441913 in words is "twenty-one million, four hundred forty-one thousand, nine hundred thirteen".