405440021012 has 48 divisors (see below), whose sum is σ = 769347128592. Its totient is φ = 185841976320.

The previous prime is 405440021011. The next prime is 405440021027. The reversal of 405440021012 is 210120044504.

It can be written as a sum of positive squares in 8 ways, for example, as 25732651396 + 379707369616 = 160414^2 + 616204^2 .

It is a super-2 number, since 2×405440021012² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405440021011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18055712 + ... + 18078152.

It is an arithmetic number, because the mean of its divisors is an integer number (16028065179).

Almost surely, 2^405440021012 is an apocalyptic number.

It is an amenable number.

405440021012 is a deficient number, since it is larger than the sum of its proper divisors (363907107580).

405440021012 is a wasteful number, since it uses less digits than its factorization.

405440021012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24828 (or 24826 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 23.

Adding to 405440021012 its reverse (210120044504), we get a palindrome (615560065516).

The spelling of 405440021012 in words is "four hundred five billion, four hundred forty million, twenty-one thousand, twelve".