21001000244 has 24 divisors (see below), whose sum is σ = 42005936448. Its totient is φ = 8999585280.

The previous prime is 21001000213. The next prime is 21001000253. The reversal of 21001000244 is 44200010012.

It is a super-4 number, since 4×21001000244⁴ (a number of 42 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 338807 + ... + 395969.

It is an arithmetic number, because the mean of its divisors is an integer number (1750247352).

Almost surely, 2^21001000244 is an apocalyptic number.

It is an amenable number.

21001000244 is an abundant number, since it is smaller than the sum of its proper divisors (21004936204).

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

21001000244 is a wasteful number, since it uses less digits than its factorization.

21001000244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70295 (or 70293 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21001000244 its reverse (44200010012), we get a palindrome (65201010256).

The spelling of 21001000244 in words is "twenty-one billion, one million, two hundred forty-four", and thus it is an aban number.