21545113215 has 8 divisors (see below), whose sum is σ = 34472181168. Its totient is φ = 11490727040.

The previous prime is 21545113199. The next prime is 21545113241. The reversal of 21545113215 is 51231154512.

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

It is not a de Polignac number, because 21545113215 - 2⁴ = 21545113199 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 718170426 + ... + 718170455.

It is an arithmetic number, because the mean of its divisors is an integer number (4309022646).

Almost surely, 2^21545113215 is an apocalyptic number.

21545113215 is a deficient number, since it is larger than the sum of its proper divisors (12927067953).

21545113215 is a wasteful number, since it uses less digits than its factorization.

21545113215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1436340889.

The product of its digits is 6000, while the sum is 30.

Adding to 21545113215 its reverse (51231154512), we get a palindrome (72776267727).

The spelling of 21545113215 in words is "twenty-one billion, five hundred forty-five million, one hundred thirteen thousand, two hundred fifteen".