21010145244 has 72 divisors (see below), whose sum is σ = 53931623424. Its totient is φ = 6361264800.

The previous prime is 21010145203. The next prime is 21010145281. The reversal of 21010145244 is 44254101012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1892229 + ... + 1903299.

Almost surely, 2^21010145244 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21010145244, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26965811712).

21010145244 is an abundant number, since it is smaller than the sum of its proper divisors (32921478180).

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

21010145244 is a wasteful number, since it uses less digits than its factorization.

21010145244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12407 (or 12394 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

Adding to 21010145244 its reverse (44254101012), we get a palindrome (65264246256).

The spelling of 21010145244 in words is "twenty-one billion, ten million, one hundred forty-five thousand, two hundred forty-four".