21030400044 has 18 divisors (see below), whose sum is σ = 53160177980. Its totient is φ = 7010133336.

The previous prime is 21030400043. The next prime is 21030400063. The reversal of 21030400044 is 44000403012.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21030400043) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 292088854 + ... + 292088925.

Almost surely, 2^21030400044 is an apocalyptic number.

It is an amenable number.

21030400044 is an abundant number, since it is smaller than the sum of its proper divisors (32129777936).

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

21030400044 is a wasteful number, since it uses less digits than its factorization.

21030400044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 584177789 (or 584177784 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 21030400044 its reverse (44000403012), we get a palindrome (65030803056).

The spelling of 21030400044 in words is "twenty-one billion, thirty million, four hundred thousand, forty-four".