21165213013 has 8 divisors (see below), whose sum is σ = 24205093632. Its totient is φ = 18129402096.

The previous prime is 21165212977. The next prime is 21165213089. The reversal of 21165213013 is 31031256112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21165213013 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 (21165213413) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1006270 + ... + 1027087.

It is an arithmetic number, because the mean of its divisors is an integer number (3025636704).

Almost surely, 2^21165213013 is an apocalyptic number.

It is an amenable number.

21165213013 is a deficient number, since it is larger than the sum of its proper divisors (3039880619).

21165213013 is a wasteful number, since it uses less digits than its factorization.

21165213013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2034851.

The product of its (nonzero) digits is 1080, while the sum is 25.

Adding to 21165213013 its reverse (31031256112), we get a palindrome (52196469125).

The spelling of 21165213013 in words is "twenty-one billion, one hundred sixty-five million, two hundred thirteen thousand, thirteen".