404121639 has 4 divisors (see below), whose sum is σ = 538828856. Its totient is φ = 269414424.

The previous prime is 404121631. The next prime is 404121647. The reversal of 404121639 is 936121404.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (404121631) and next prime (404121647).

It is not a de Polignac number, because 404121639 - 2³ = 404121631 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 (404121631) 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, 67353604 + ... + 67353609.

It is an arithmetic number, because the mean of its divisors is an integer number (134707214).

Almost surely, 2^404121639 is an apocalyptic number.

404121639 is a deficient number, since it is larger than the sum of its proper divisors (134707217).

404121639 is a wasteful number, since it uses less digits than its factorization.

404121639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134707216.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 404121639 is about 20102.7768977323. The cubic root of 404121639 is about 739.3283649105.

The spelling of 404121639 in words is "four hundred four million, one hundred twenty-one thousand, six hundred thirty-nine".