21004144402 has 16 divisors (see below), whose sum is σ = 33371584632. Its totient is φ = 9880729600.

The previous prime is 21004144393. The next prime is 21004144429. The reversal of 21004144402 is 20444140012.

It can be written as a sum of positive squares in 4 ways, for example, as 19985194161 + 1018950241 = 141369^2 + 31921^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15043 + ... + 205510.

Almost surely, 2^21004144402 is an apocalyptic number.

21004144402 is a deficient number, since it is larger than the sum of its proper divisors (12367440230).

21004144402 is a wasteful number, since it uses less digits than its factorization.

21004144402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223373.

The product of its (nonzero) digits is 1024, while the sum is 22.

Adding to 21004144402 its reverse (20444140012), we get a palindrome (41448284414).

The spelling of 21004144402 in words is "twenty-one billion, four million, one hundred forty-four thousand, four hundred two".