21511466013 has 24 divisors (see below), whose sum is σ = 30024803200. Its totient is φ = 13698432000.

The previous prime is 21511465973. The next prime is 21511466051. The reversal of 21511466013 is 31066411512.

It is a happy number.

It is not a de Polignac number, because 21511466013 - 2⁶ = 21511465949 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 (21511446013) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1182813 + ... + 1200861.

Almost surely, 2^21511466013 is an apocalyptic number.

21511466013 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21511466013 is a deficient number, since it is larger than the sum of its proper divisors (8513337187).

21511466013 is a wasteful number, since it uses less digits than its factorization.

21511466013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18849 (or 18826 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

Adding to 21511466013 its reverse (31066411512), we get a palindrome (52577877525).

The spelling of 21511466013 in words is "twenty-one billion, five hundred eleven million, four hundred sixty-six thousand, thirteen".