21407441 has 6 divisors (see below), whose sum is σ = 23530626. Its totient is φ = 19461200.

The previous prime is 21407387. The next prime is 21407467. The reversal of 21407441 is 14470412.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 18309841 + 3097600 = 4279^2 + 1760^2 .

It is not a de Polignac number, because 21407441 - 2⁶ = 21407377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21407041) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 88340 + ... + 88581.

It is an arithmetic number, because the mean of its divisors is an integer number (3921771).

Almost surely, 2^21407441 is an apocalyptic number.

It is an amenable number.

21407441 is a deficient number, since it is larger than the sum of its proper divisors (2123185).

21407441 is a wasteful number, since it uses less digits than its factorization.

21407441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176943 (or 176932 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 21407441 is about 4626.8175887969. The cubic root of 21407441 is about 277.6652847545.

Adding to 21407441 its reverse (14470412), we get a palindrome (35877853).

The spelling of 21407441 in words is "twenty-one million, four hundred seven thousand, four hundred forty-one".