40181221 has 8 divisors (see below), whose sum is σ = 41225184. Its totient is φ = 39142320.

The previous prime is 40181191. The next prime is 40181233. The reversal of 40181221 is 12218104.

It is a happy number.

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 40181221 - 2⁷ = 40181093 is a prime.

It is a super-2 number, since 2×40181221² = 3229061042101682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40181291) 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, 18810 + ... + 20836.

It is an arithmetic number, because the mean of its divisors is an integer number (5153148).

Almost surely, 2^40181221 is an apocalyptic number.

It is an amenable number.

40181221 is a deficient number, since it is larger than the sum of its proper divisors (1043963).

40181221 is a wasteful number, since it uses less digits than its factorization.

40181221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2531.

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

The square root of 40181221 is about 6338.8659080312. The cubic root of 40181221 is about 342.5108839136.

Adding to 40181221 its reverse (12218104), we get a palindrome (52399325).

The spelling of 40181221 in words is "forty million, one hundred eighty-one thousand, two hundred twenty-one".