21251134203415 has 16 divisors (see below), whose sum is σ = 25597482200928. Its totient is φ = 16936888790016.

The previous prime is 21251134203401. The next prime is 21251134203451. The reversal of 21251134203415 is 51430243115212.

It is a cyclic number.

It is not a de Polignac number, because 21251134203415 - 2²¹ = 21251132106263 is a prime.

It is a super-2 number, since 2×21251134203415² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1152322 + ... + 6620431.

It is an arithmetic number, because the mean of its divisors is an integer number (1599842637558).

Almost surely, 2^{21251134203415} is an apocalyptic number.

21251134203415 is a deficient number, since it is larger than the sum of its proper divisors (4346347997513).

21251134203415 is a wasteful number, since it uses less digits than its factorization.

21251134203415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7774818.

The product of its (nonzero) digits is 28800, while the sum is 34.

Adding to 21251134203415 its reverse (51430243115212), we get a palindrome (72681377318627).

The spelling of 21251134203415 in words is "twenty-one trillion, two hundred fifty-one billion, one hundred thirty-four million, two hundred three thousand, four hundred fifteen".