21207741 has 16 divisors (see below), whose sum is σ = 28877760. Its totient is φ = 13841280.

The previous prime is 21207733. The next prime is 21207749. The reversal of 21207741 is 14770212.

It is an interprime number because it is at equal distance from previous prime (21207733) and next prime (21207749).

It is not a de Polignac number, because 21207741 - 2³ = 21207733 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21207749) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38931 + ... + 39471.

It is an arithmetic number, because the mean of its divisors is an integer number (1804860).

Almost surely, 2^21207741 is an apocalyptic number.

It is an amenable number.

21207741 is a deficient number, since it is larger than the sum of its proper divisors (7670019).

21207741 is a wasteful number, since it uses less digits than its factorization.

21207741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 796.

The product of its (nonzero) digits is 784, while the sum is 24.

The square root of 21207741 is about 4605.1863154491. The cubic root of 21207741 is about 276.7991828205.

Adding to 21207741 its reverse (14770212), we get a palindrome (35977953).

The spelling of 21207741 in words is "twenty-one million, two hundred seven thousand, seven hundred forty-one".