21450545636 has 24 divisors (see below), whose sum is σ = 41286161280. Its totient is φ = 9689607072.

The previous prime is 21450545609. The next prime is 21450545639. The reversal of 21450545636 is 63654505412.

It is a happy number.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21450545593 and 21450545602.

It is not an unprimeable number, because it can be changed into a prime (21450545639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4385966 + ... + 4390853.

It is an arithmetic number, because the mean of its divisors is an integer number (1720256720).

Almost surely, 2^21450545636 is an apocalyptic number.

21450545636 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21450545636 is a deficient number, since it is larger than the sum of its proper divisors (19835615644).

21450545636 is a wasteful number, since it uses less digits than its factorization.

21450545636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8776883 (or 8776881 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 41.

The spelling of 21450545636 in words is "twenty-one billion, four hundred fifty million, five hundred forty-five thousand, six hundred thirty-six".