21010510444 has 24 divisors (see below), whose sum is σ = 45841114368. Its totient is φ = 8185913040.

The previous prime is 21010510429. The next prime is 21010510447. The reversal of 21010510444 is 44401501012.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (21010510447) by changing a digit.

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, 34107664 + ... + 34108279.

It is an arithmetic number, because the mean of its divisors is an integer number (1910046432).

Almost surely, 2^21010510444 is an apocalyptic number.

It is an amenable number.

21010510444 is an abundant number, since it is smaller than the sum of its proper divisors (24830603924).

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

21010510444 is a wasteful number, since it uses less digits than its factorization.

21010510444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68215965 (or 68215963 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The spelling of 21010510444 in words is "twenty-one billion, ten million, five hundred ten thousand, four hundred forty-four".