21121112404 has 48 divisors (see below), whose sum is σ = 42998376960. Its totient is φ = 8890161120.

The previous prime is 21121112399. The next prime is 21121112413. The reversal of 21121112404 is 40421112112.

It is a happy number.

It is a super-2 number, since 2×21121112404² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1955539 + ... + 1966309.

It is an arithmetic number, because the mean of its divisors is an integer number (895799520).

Almost surely, 2^21121112404 is an apocalyptic number.

It is an amenable number.

21121112404 is an abundant number, since it is smaller than the sum of its proper divisors (21877264556).

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

21121112404 is a wasteful number, since it uses less digits than its factorization.

21121112404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12028 (or 12026 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21121112404 its reverse (40421112112), we get a palindrome (61542224516).

The spelling of 21121112404 in words is "twenty-one billion, one hundred twenty-one million, one hundred twelve thousand, four hundred four".