21261741 has 16 divisors (see below), whose sum is σ = 30114240. Its totient is φ = 13305600.

The previous prime is 21261707. The next prime is 21261767. The reversal of 21261741 is 14716212.

It is not a de Polignac number, because 21261741 - 2⁶ = 21261677 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21261701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4791 + ... + 8091.

It is an arithmetic number, because the mean of its divisors is an integer number (1882140).

Almost surely, 2^21261741 is an apocalyptic number.

It is an amenable number.

21261741 is a deficient number, since it is larger than the sum of its proper divisors (8852499).

21261741 is a wasteful number, since it uses less digits than its factorization.

21261741 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3436.

The product of its digits is 672, while the sum is 24.

The square root of 21261741 is about 4611.0455430412. The cubic root of 21261741 is about 277.0339160946.

Adding to 21261741 its reverse (14716212), we get a palindrome (35977953).

The spelling of 21261741 in words is "twenty-one million, two hundred sixty-one thousand, seven hundred forty-one".