40420421 has 4 divisors (see below), whose sum is σ = 40436352. Its totient is φ = 40404492.

The previous prime is 40420411. The next prime is 40420433. The reversal of 40420421 is 12402404.

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 a cyclic number.

It is not a de Polignac number, because 40420421 - 2⁶ = 40420357 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 40420421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40420411) 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, 3215 + ... + 9548.

It is an arithmetic number, because the mean of its divisors is an integer number (10109088).

Almost surely, 2^40420421 is an apocalyptic number.

It is an amenable number.

40420421 is a deficient number, since it is larger than the sum of its proper divisors (15931).

40420421 is a wasteful number, since it uses less digits than its factorization.

40420421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15930.

The product of its (nonzero) digits is 256, while the sum is 17.

The square root of 40420421 is about 6357.7056396156. The cubic root of 40420421 is about 343.1891988286.

Adding to 40420421 its reverse (12402404), we get a palindrome (52822825).

The spelling of 40420421 in words is "forty million, four hundred twenty thousand, four hundred twenty-one".