21404350213 has 4 divisors (see below), whose sum is σ = 21644848620. Its totient is φ = 21163851808.

The previous prime is 21404350181. The next prime is 21404350271. The reversal of 21404350213 is 31205340412.

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 14558111649 + 6846238564 = 120657^2 + 82742^2 .

It is a cyclic number.

It is not a de Polignac number, because 21404350213 - 2⁵ = 21404350181 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21404350013) 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, 120249070 + ... + 120249247.

It is an arithmetic number, because the mean of its divisors is an integer number (5411212155).

Almost surely, 2^21404350213 is an apocalyptic number.

It is an amenable number.

21404350213 is a deficient number, since it is larger than the sum of its proper divisors (240498407).

21404350213 is an equidigital number, since it uses as much as digits as its factorization.

21404350213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240498406.

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 21404350213 its reverse (31205340412), we get a palindrome (52609690625).

The spelling of 21404350213 in words is "twenty-one billion, four hundred four million, three hundred fifty thousand, two hundred thirteen".