21650050013 has 4 divisors (see below), whose sum is σ = 21661513020. Its totient is φ = 21638587008.

The previous prime is 21650049997. The next prime is 21650050027. The reversal of 21650050013 is 31005005612.

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 13957532164 + 7692517849 = 118142^2 + 87707^2 .

It is a cyclic number.

It is not a de Polignac number, because 21650050013 - 2⁴ = 21650049997 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 (21650055013) 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, 5728670 + ... + 5732447.

It is an arithmetic number, because the mean of its divisors is an integer number (5415378255).

Almost surely, 2^21650050013 is an apocalyptic number.

It is an amenable number.

21650050013 is a deficient number, since it is larger than the sum of its proper divisors (11463007).

21650050013 is a wasteful number, since it uses less digits than its factorization.

21650050013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11463006.

The product of its (nonzero) digits is 900, while the sum is 23.

Adding to 21650050013 its reverse (31005005612), we get a palindrome (52655055625).

The spelling of 21650050013 in words is "twenty-one billion, six hundred fifty million, fifty thousand, thirteen".