21545113216 has 32 divisors (see below), whose sum is σ = 46823899680. Its totient is φ = 9793232640.

The previous prime is 21545113199. The next prime is 21545113241. The reversal of 21545113216 is 61231154512.

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7649556 + ... + 7652371.

It is an arithmetic number, because the mean of its divisors is an integer number (1463246865).

Almost surely, 2^21545113216 is an apocalyptic number.

It is an amenable number.

21545113216 is an abundant number, since it is smaller than the sum of its proper divisors (25278786464).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21545113216 is a wasteful number, since it uses less digits than its factorization.

21545113216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15301952 (or 15301940 counting only the distinct ones).

The product of its digits is 7200, while the sum is 31.

Adding to 21545113216 its reverse (61231154512), we get a palindrome (82776267728).

The spelling of 21545113216 in words is "twenty-one billion, five hundred forty-five million, one hundred thirteen thousand, two hundred sixteen".