21741213 has 32 divisors (see below), whose sum is σ = 33062400. Its totient is φ = 12612096.

The previous prime is 21741197. The next prime is 21741217. The reversal of 21741213 is 31214712.

It is not a de Polignac number, because 21741213 - 2⁴ = 21741197 is a prime.

It is a super-2 number, since 2×21741213² = 945360685422738, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21741213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21741217) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52953 + ... + 53361.

It is an arithmetic number, because the mean of its divisors is an integer number (1033200).

Almost surely, 2^21741213 is an apocalyptic number.

It is an amenable number.

21741213 is a deficient number, since it is larger than the sum of its proper divisors (11321187).

21741213 is a wasteful number, since it uses less digits than its factorization.

21741213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 501.

The product of its digits is 336, while the sum is 21.

The square root of 21741213 is about 4662.7473660922. The cubic root of 21741213 is about 279.1009128671.

Adding to 21741213 its reverse (31214712), we get a palindrome (52955925).

The spelling of 21741213 in words is "twenty-one million, seven hundred forty-one thousand, two hundred thirteen".