21105245415 has 16 divisors (see below), whose sum is σ = 33840713088. Its totient is φ = 11232024096.

The previous prime is 21105245411. The next prime is 21105245489. The reversal of 21105245415 is 51454250112.

It is not a de Polignac number, because 21105245415 - 2² = 21105245411 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21105245411) 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, 1499437 + ... + 1513446.

It is an arithmetic number, because the mean of its divisors is an integer number (2115044568).

Almost surely, 2^21105245415 is an apocalyptic number.

21105245415 is a deficient number, since it is larger than the sum of its proper divisors (12735467673).

21105245415 is a wasteful number, since it uses less digits than its factorization.

21105245415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3013358.

The product of its (nonzero) digits is 8000, while the sum is 30.

Adding to 21105245415 its reverse (51454250112), we get a palindrome (72559495527).

The spelling of 21105245415 in words is "twenty-one billion, one hundred five million, two hundred forty-five thousand, four hundred fifteen".