21453635412 has 54 divisors (see below), whose sum is σ = 59608219034. Its totient is φ = 6501100320.

The previous prime is 21453635377. The next prime is 21453635419.

21453635412 is a `hidden beast` number, since 2 + 1 + 4 + 5 + 3 + 635 + 4 + 12 = 666.

21453635412 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in only one way, i.e., 14603755716 + 6849879696 = 120846^2 + 82764^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21453635419) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 2458183 + ... + 2466894.

Almost surely, 2^21453635412 is an apocalyptic number.

21453635412 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21453635412 is an abundant number, since it is smaller than the sum of its proper divisors (38154583622).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21453635412 is a wasteful number, since it uses less digits than its factorization.

21453635412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4925109 (or 4925093 counting only the distinct ones).

The product of its digits is 86400, while the sum is 36.

The spelling of 21453635412 in words is "twenty-one billion, four hundred fifty-three million, six hundred thirty-five thousand, four hundred twelve".