40217321 has 4 divisors (see below), whose sum is σ = 40230144. Its totient is φ = 40204500.

The previous prime is 40217299. The next prime is 40217327. The reversal of 40217321 is 12371204.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 40217321 - 2¹⁸ = 39955177 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40217293 and 40217302.

It is not an unprimeable number, because it can be changed into a prime (40217327) 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, 1796 + ... + 9146.

It is an arithmetic number, because the mean of its divisors is an integer number (10057536).

Almost surely, 2^40217321 is an apocalyptic number.

It is an amenable number.

40217321 is a deficient number, since it is larger than the sum of its proper divisors (12823).

40217321 is an equidigital number, since it uses as much as digits as its factorization.

40217321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12822.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 40217321 is about 6341.7127812603. The cubic root of 40217321 is about 342.6134271874.

Adding to 40217321 its reverse (12371204), we get a palindrome (52588525).

The spelling of 40217321 in words is "forty million, two hundred seventeen thousand, three hundred twenty-one".