3998640 has 40 divisors (see below), whose sum is σ = 12396528. Its totient is φ = 1066240.

The previous prime is 3998639. The next prime is 3998641. The reversal of 3998640 is 468993.

It is an interprime number because it is at equal distance from previous prime (3998639) and next prime (3998641).

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (3998641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8091 + ... + 8570.

Almost surely, 2^3998640 is an apocalyptic number.

3998640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

3998640 is an abundant number, since it is smaller than the sum of its proper divisors (8397888).

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

3998640 is a wasteful number, since it uses less digits than its factorization.

3998640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16677 (or 16671 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 3998640 is about 1999.6599710951. The cubic root of 3998640 is about 158.7221126123.

The spelling of 3998640 in words is "three million, nine hundred ninety-eight thousand, six hundred forty".