40021312 has 28 divisors (see below), whose sum is σ = 80159860. Its totient is φ = 19823616.

The previous prime is 40021273. The next prime is 40021313. The reversal of 40021312 is 21312004.

It can be written as a sum of positive squares in 2 ways, for example, as 10601536 + 29419776 = 3256^2 + 5424^2 .

It is a junction number, because it is equal to n+sod(n) for n = 40021292 and 40021301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40021313) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4108 + ... + 9844.

Almost surely, 2^40021312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 40021312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40079930).

40021312 is an abundant number, since it is smaller than the sum of its proper divisors (40138548).

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

40021312 is a wasteful number, since it uses less digits than its factorization.

40021312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5858 (or 5848 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 40021312 is about 6326.2399575103. The cubic root of 40021312 is about 342.0559168970.

Adding to 40021312 its reverse (21312004), we get a palindrome (61333316).

It can be divided in two parts, 400 and 21312, that added together give a palindrome (21712).

The spelling of 40021312 in words is "forty million, twenty-one thousand, three hundred twelve".