21350400013 has 4 divisors (see below), whose sum is σ = 21486389980. Its totient is φ = 21214410048.

The previous prime is 21350399929. The next prime is 21350400023. The reversal of 21350400013 is 31000405312.

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 6580129924 + 14770270089 = 81118^2 + 121533^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21350400013 is a prime.

It is a super-2 number, since 2×21350400013² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21350400023) 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, 67994748 + ... + 67995061.

It is an arithmetic number, because the mean of its divisors is an integer number (5371597495).

Almost surely, 2^21350400013 is an apocalyptic number.

It is an amenable number.

21350400013 is a deficient number, since it is larger than the sum of its proper divisors (135989967).

21350400013 is a wasteful number, since it uses less digits than its factorization.

21350400013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135989966.

The product of its (nonzero) digits is 360, while the sum is 19.

Adding to 21350400013 its reverse (31000405312), we get a palindrome (52350805325).

The spelling of 21350400013 in words is "twenty-one billion, three hundred fifty million, four hundred thousand, thirteen".