40478639 has 4 divisors (see below), whose sum is σ = 40491960. Its totient is φ = 40465320.

The previous prime is 40478621. The next prime is 40478651. The reversal of 40478639 is 93687404.

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.

It is a cyclic number.

It is not a de Polignac number, because 40478639 - 2¹² = 40474543 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40478596 and 40478605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40478699) 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, 377 + ... + 9005.

It is an arithmetic number, because the mean of its divisors is an integer number (10122990).

Almost surely, 2^40478639 is an apocalyptic number.

40478639 is a deficient number, since it is larger than the sum of its proper divisors (13321).

40478639 is an equidigital number, since it uses as much as digits as its factorization.

40478639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13320.

The product of its (nonzero) digits is 145152, while the sum is 41.

The square root of 40478639 is about 6362.2825306646. The cubic root of 40478639 is about 343.3538862446.

The spelling of 40478639 in words is "forty million, four hundred seventy-eight thousand, six hundred thirty-nine".