21513501234404 has 12 divisors (see below), whose sum is σ = 39863252287404. Its totient is φ = 10124000580864.

The previous prime is 21513501234391. The next prime is 21513501234461. The reversal of 21513501234404 is 40443210531512.

It can be written as a sum of positive squares in 2 ways, for example, as 18782255822500 + 2731245411904 = 4333850^2 + 1652648^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158187509009 + ... + 158187509144.

It is an arithmetic number, because the mean of its divisors is an integer number (3321937690617).

Almost surely, 2^{21513501234404} is an apocalyptic number.

It is an amenable number.

21513501234404 is a deficient number, since it is larger than the sum of its proper divisors (18349751053000).

21513501234404 is a wasteful number, since it uses less digits than its factorization.

21513501234404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316375018174 (or 316375018172 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 35.

Adding to 21513501234404 its reverse (40443210531512), we get a palindrome (61956711765916).

The spelling of 21513501234404 in words is "twenty-one trillion, five hundred thirteen billion, five hundred one million, two hundred thirty-four thousand, four hundred four".