40131221 has 8 divisors (see below), whose sum is σ = 43407000. Its totient is φ = 36882432.

The previous prime is 40131209. The next prime is 40131227. The reversal of 40131221 is 12213104.

It can be written as a sum of positive squares in 4 ways, for example, as 302500 + 39828721 = 550^2 + 6311^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 40131221 - 2¹⁰ = 40130197 is a prime.

It is a super-2 number, since 2×40131221² = 3221029797901682, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 40131196 and 40131205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40131227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3596 + ... + 9653.

It is an arithmetic number, because the mean of its divisors is an integer number (5425875).

Almost surely, 2^40131221 is an apocalyptic number.

It is an amenable number.

40131221 is a deficient number, since it is larger than the sum of its proper divisors (3275779).

40131221 is a wasteful number, since it uses less digits than its factorization.

40131221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13495.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 40131221 is about 6334.9207571997. The cubic root of 40131221 is about 342.3687557242.

Adding to 40131221 its reverse (12213104), we get a palindrome (52344325).

The spelling of 40131221 in words is "forty million, one hundred thirty-one thousand, two hundred twenty-one".