21515040144405 has 48 divisors (see below), whose sum is σ = 37530064091520. Its totient is φ = 11401715481984.

The previous prime is 21515040144379. The next prime is 21515040144407. The reversal of 21515040144405 is 50444104051512.

21515040144405 is a `hidden beast` number, since 2 + 1 + 5 + 1 + 504 + 0 + 144 + 4 + 0 + 5 = 666.

It is not a de Polignac number, because 21515040144405 - 2²² = 21515035950101 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21515040144405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21515040144407) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 19629211 + ... + 20696279.

It is an arithmetic number, because the mean of its divisors is an integer number (781876335240).

Almost surely, 2^{21515040144405} is an apocalyptic number.

It is an amenable number.

21515040144405 is a deficient number, since it is larger than the sum of its proper divisors (16015023947115).

21515040144405 is a wasteful number, since it uses less digits than its factorization.

21515040144405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1069930 (or 1069927 counting only the distinct ones).

The product of its (nonzero) digits is 64000, while the sum is 36.

Adding to 21515040144405 its reverse (50444104051512), we get a palindrome (71959144195917).

The spelling of 21515040144405 in words is "twenty-one trillion, five hundred fifteen billion, forty million, one hundred forty-four thousand, four hundred five".