438649391 has 4 divisors (see below), whose sum is σ = 438703032. Its totient is φ = 438595752.

The previous prime is 438649373. The next prime is 438649417. The reversal of 438649391 is 193946834.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 193946834 = 2 ⋅96973417.

It is a cyclic number.

It is not a de Polignac number, because 438649391 - 2⁶ = 438649327 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 (438649301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11720 + ... + 31853.

It is an arithmetic number, because the mean of its divisors is an integer number (109675758).

Almost surely, 2^438649391 is an apocalyptic number.

438649391 is a deficient number, since it is larger than the sum of its proper divisors (53641).

438649391 is a wasteful number, since it uses less digits than its factorization.

438649391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53640.

The product of its digits is 559872, while the sum is 47.

The square root of 438649391 is about 20943.9583412496. The cubic root of 438649391 is about 759.8114669695.

The spelling of 438649391 in words is "four hundred thirty-eight million, six hundred forty-nine thousand, three hundred ninety-one".