21105015453 has 16 divisors (see below), whose sum is σ = 32912305600. Its totient is φ = 13329483120.

The previous prime is 21105015431. The next prime is 21105015479. The reversal of 21105015453 is 35451050112.

21105015453 is a `hidden beast` number, since 2 + 110 + 5 + 0 + 1 + 545 + 3 = 666.

It is not a de Polignac number, because 21105015453 - 2¹² = 21105011357 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21105015403) 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, 20569678 + ... + 20570703.

It is an arithmetic number, because the mean of its divisors is an integer number (2057019100).

Almost surely, 2^21105015453 is an apocalyptic number.

It is an amenable number.

21105015453 is a deficient number, since it is larger than the sum of its proper divisors (11807290147).

21105015453 is a wasteful number, since it uses less digits than its factorization.

21105015453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41140409 (or 41140403 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

Adding to 21105015453 its reverse (35451050112), we get a palindrome (56556065565).

The spelling of 21105015453 in words is "twenty-one billion, one hundred five million, fifteen thousand, four hundred fifty-three".