21042241450 has 12 divisors (see below), whose sum is σ = 39138569190. Its totient is φ = 8416896560.

The previous prime is 21042241447. The next prime is 21042241471. The reversal of 21042241450 is 5414224012.

It can be written as a sum of positive squares in 3 ways, for example, as 15031495609 + 6010745841 = 122603^2 + 77529^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 210422365 + ... + 210422464.

Almost surely, 2^21042241450 is an apocalyptic number.

21042241450 is a deficient number, since it is larger than the sum of its proper divisors (18096327740).

21042241450 is a wasteful number, since it uses less digits than its factorization.

21042241450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420844841 (or 420844836 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 21042241450 its reverse (5414224012), we get a palindrome (26456465462).

The spelling of 21042241450 in words is "twenty-one billion, forty-two million, two hundred forty-one thousand, four hundred fifty".