21404123412 has 24 divisors (see below), whose sum is σ = 57077662656. Its totient is φ = 6115463808.

The previous prime is 21404123381. The next prime is 21404123437. The reversal of 21404123412 is 21432140412.

It is a super-2 number, since 2×21404123412² (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 7 ways as a sum of consecutive naturals, for example, 127405413 + ... + 127405580.

It is an arithmetic number, because the mean of its divisors is an integer number (2378235944).

Almost surely, 2^21404123412 is an apocalyptic number.

It is an amenable number.

21404123412 is an abundant number, since it is smaller than the sum of its proper divisors (35673539244).

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

21404123412 is a wasteful number, since it uses less digits than its factorization.

21404123412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254811007 (or 254811005 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

Adding to 21404123412 its reverse (21432140412), we get a palindrome (42836263824).

The spelling of 21404123412 in words is "twenty-one billion, four hundred four million, one hundred twenty-three thousand, four hundred twelve".