21100356013 has 4 divisors (see below), whose sum is σ = 23018570208. Its totient is φ = 19182141820.

The previous prime is 21100356001. The next prime is 21100356047. The reversal of 21100356013 is 31065300112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21100356013 - 2³³ = 12510421421 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 (21100350013) 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, 959107081 + ... + 959107102.

It is an arithmetic number, because the mean of its divisors is an integer number (5754642552).

Almost surely, 2^21100356013 is an apocalyptic number.

It is an amenable number.

21100356013 is a deficient number, since it is larger than the sum of its proper divisors (1918214195).

21100356013 is a wasteful number, since it uses less digits than its factorization.

21100356013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1918214194.

The product of its (nonzero) digits is 540, while the sum is 22.

Adding to 21100356013 its reverse (31065300112), we get a palindrome (52165656125).

The spelling of 21100356013 in words is "twenty-one billion, one hundred million, three hundred fifty-six thousand, thirteen".