6387440 has 20 divisors (see below), whose sum is σ = 14850984. Its totient is φ = 2554944.

The previous prime is 6387413. The next prime is 6387449. The reversal of 6387440 is 447836.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 6387397 and 6387406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6387449) 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, 39842 + ... + 40001.

Almost surely, 2^6387440 is an apocalyptic number.

It is an amenable number.

6387440 is an abundant number, since it is smaller than the sum of its proper divisors (8463544).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6387440 is a wasteful number, since it uses less digits than its factorization.

6387440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79856 (or 79850 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 32.

The square root of 6387440 is about 2527.3385210533. The cubic root of 6387440 is about 185.5420188982.

The spelling of 6387440 in words is "six million, three hundred eighty-seven thousand, four hundred forty".