40217421 has 4 divisors (see below), whose sum is σ = 53623232. Its totient is φ = 26811612.

The previous prime is 40217377. The next prime is 40217449. The reversal of 40217421 is 12471204.

It is a happy number.

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.

It is not a de Polignac number, because 40217421 - 2⁷ = 40217293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40213421) 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, 6702901 + ... + 6702906.

It is an arithmetic number, because the mean of its divisors is an integer number (13405808).

Almost surely, 2^40217421 is an apocalyptic number.

It is an amenable number.

40217421 is a deficient number, since it is larger than the sum of its proper divisors (13405811).

40217421 is a wasteful number, since it uses less digits than its factorization.

40217421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13405810.

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 40217421 is about 6341.7206655607. The cubic root of 40217421 is about 342.6137111555.

Adding to 40217421 its reverse (12471204), we get a palindrome (52688625).

The spelling of 40217421 in words is "forty million, two hundred seventeen thousand, four hundred twenty-one".