406637421 has 4 divisors (see below), whose sum is σ = 542183232. Its totient is φ = 271091612.

The previous prime is 406637327. The next prime is 406637431. The reversal of 406637421 is 124736604.

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 a cyclic number.

It is not a de Polignac number, because 406637421 - 2¹¹ = 406635373 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (406637431) 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, 67772901 + ... + 67772906.

It is an arithmetic number, because the mean of its divisors is an integer number (135545808).

Almost surely, 2^406637421 is an apocalyptic number.

It is an amenable number.

406637421 is a deficient number, since it is larger than the sum of its proper divisors (135545811).

406637421 is a wasteful number, since it uses less digits than its factorization.

406637421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135545810.

The product of its (nonzero) digits is 24192, while the sum is 33.

The square root of 406637421 is about 20165.2528126974. The cubic root of 406637421 is about 740.8593747504.

It can be divided in two parts, 40663 and 7421, that added together give a palindrome (48084).

The spelling of 406637421 in words is "four hundred six million, six hundred thirty-seven thousand, four hundred twenty-one".