21512415104263 has 16 divisors (see below), whose sum is σ = 22057843691520. Its totient is φ = 20973650349600.

The previous prime is 21512415104239. The next prime is 21512415104393. The reversal of 21512415104263 is 36240151421512.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21512415104263 is a prime.

It is a super-2 number, since 2×21512415104263² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21512415104203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1174698 + ... + 6663688.

It is an arithmetic number, because the mean of its divisors is an integer number (1378615230720).

Almost surely, 2^{21512415104263} is an apocalyptic number.

21512415104263 is a deficient number, since it is larger than the sum of its proper divisors (545428587257).

21512415104263 is a wasteful number, since it uses less digits than its factorization.

21512415104263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5489598.

The product of its (nonzero) digits is 57600, while the sum is 37.

Adding to 21512415104263 its reverse (36240151421512), we get a palindrome (57752566525775).

The spelling of 21512415104263 in words is "twenty-one trillion, five hundred twelve billion, four hundred fifteen million, one hundred four thousand, two hundred sixty-three".