21004414450 has 48 divisors (see below), whose sum is σ = 39482685000. Its totient is φ = 8312855040.

The previous prime is 21004414439. The next prime is 21004414463. The reversal of 21004414450 is 5441440012.

It can be written as a sum of positive squares in 12 ways, for example, as 8910793609 + 12093620841 = 94397^2 + 109971^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4515726 + ... + 4520374.

Almost surely, 2^21004414450 is an apocalyptic number.

21004414450 is a deficient number, since it is larger than the sum of its proper divisors (18478270550).

21004414450 is a wasteful number, since it uses less digits than its factorization.

21004414450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5599 (or 5594 counting only the distinct ones).

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

Adding to 21004414450 its reverse (5441440012), we get a palindrome (26445854462).

The spelling of 21004414450 in words is "twenty-one billion, four million, four hundred fourteen thousand, four hundred fifty".