21540314215 has 32 divisors (see below), whose sum is σ = 29996467200. Its totient is φ = 14544313344.

The previous prime is 21540314207. The next prime is 21540314249. The reversal of 21540314215 is 51241304512.

It is a cyclic number.

It is not a de Polignac number, because 21540314215 - 2³ = 21540314207 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 659664 + ... + 691546.

It is an arithmetic number, because the mean of its divisors is an integer number (937389600).

Almost surely, 2^21540314215 is an apocalyptic number.

21540314215 is a deficient number, since it is larger than the sum of its proper divisors (8456152985).

21540314215 is a wasteful number, since it uses less digits than its factorization.

21540314215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32191.

The product of its (nonzero) digits is 4800, while the sum is 28.

Adding to 21540314215 its reverse (51241304512), we get a palindrome (72781618727).

The spelling of 21540314215 in words is "twenty-one billion, five hundred forty million, three hundred fourteen thousand, two hundred fifteen".