21530216342015 has 8 divisors (see below), whose sum is σ = 25836293064240. Its totient is φ = 17224150771072.

The previous prime is 21530216341979. The next prime is 21530216342027. The reversal of 21530216342015 is 51024361203512.

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

It is a cyclic number.

It is not a de Polignac number, because 21530216342015 - 2⁸ = 21530216341759 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, 2305892 + ... + 6955398.

It is an arithmetic number, because the mean of its divisors is an integer number (3229536633030).

Almost surely, 2^{21530216342015} is an apocalyptic number.

21530216342015 is a deficient number, since it is larger than the sum of its proper divisors (4306076722225).

21530216342015 is an equidigital number, since it uses as much as digits as its factorization.

21530216342015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5575641.

The product of its (nonzero) digits is 43200, while the sum is 35.

Adding to 21530216342015 its reverse (51024361203512), we get a palindrome (72554577545527).

The spelling of 21530216342015 in words is "twenty-one trillion, five hundred thirty billion, two hundred sixteen million, three hundred forty-two thousand, fifteen".