21004212444 has 24 divisors (see below), whose sum is σ = 51140691840. Its totient is φ = 6696995184.

The previous prime is 21004212433. The next prime is 21004212497. The reversal of 21004212444 is 44421240012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38050834 + ... + 38051385.

It is an arithmetic number, because the mean of its divisors is an integer number (2130862160).

Almost surely, 2^21004212444 is an apocalyptic number.

It is an amenable number.

21004212444 is an abundant number, since it is smaller than the sum of its proper divisors (30136479396).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21004212444 is a wasteful number, since it uses less digits than its factorization.

21004212444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76102249 (or 76102247 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 24.

Adding to 21004212444 its reverse (44421240012), we get a palindrome (65425452456).

The spelling of 21004212444 in words is "twenty-one billion, four million, two hundred twelve thousand, four hundred forty-four".