21311110044 has 60 divisors (see below), whose sum is σ = 63670236784. Its totient is φ = 6088887936.

The previous prime is 21311110013. The next prime is 21311110057. The reversal of 21311110044 is 44001111312.

It is a super-2 number, since 2×21311110044² (a number of 21 digits) contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 21311109999 and 21311110026.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4695949 + ... + 4700484.

Almost surely, 2^21311110044 is an apocalyptic number.

It is an amenable number.

21311110044 is an abundant number, since it is smaller than the sum of its proper divisors (42359126740).

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

21311110044 is a wasteful number, since it uses less digits than its factorization.

21311110044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9396456 (or 9396445 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21311110044 its reverse (44001111312), we get a palindrome (65312221356).

The spelling of 21311110044 in words is "twenty-one billion, three hundred eleven million, one hundred ten thousand, forty-four".