21540112450 has 12 divisors (see below), whose sum is σ = 40064609250. Its totient is φ = 8616044960.

The previous prime is 21540112397. The next prime is 21540112453. The reversal of 21540112450 is 5421104512.

It can be written as a sum of positive squares in 3 ways, for example, as 15753011121 + 5787101329 = 125511^2 + 76073^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (21540112453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 215401075 + ... + 215401174.

Almost surely, 2^21540112450 is an apocalyptic number.

21540112450 is a deficient number, since it is larger than the sum of its proper divisors (18524496800).

21540112450 is a wasteful number, since it uses less digits than its factorization.

21540112450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430802261 (or 430802256 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

Adding to 21540112450 its reverse (5421104512), we get a palindrome (26961216962).

The spelling of 21540112450 in words is "twenty-one billion, five hundred forty million, one hundred twelve thousand, four hundred fifty".