21643461452 has 12 divisors (see below), whose sum is σ = 37912730856. Its totient is φ = 10811252640.

The previous prime is 21643461451. The next prime is 21643461457. The reversal of 21643461452 is 25416434612.

It is not an unprimeable number, because it can be changed into a prime (21643461451) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2614874 + ... + 2623137.

It is an arithmetic number, because the mean of its divisors is an integer number (3159394238).

Almost surely, 2^21643461452 is an apocalyptic number.

It is an amenable number.

21643461452 is a deficient number, since it is larger than the sum of its proper divisors (16269269404).

21643461452 is a wasteful number, since it uses less digits than its factorization.

21643461452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5239048 (or 5239046 counting only the distinct ones).

The product of its digits is 138240, while the sum is 38.

The spelling of 21643461452 in words is "twenty-one billion, six hundred forty-three million, four hundred sixty-one thousand, four hundred fifty-two".