3990641 has 2 divisors, whose sum is σ = 3990642. Its totient is φ = 3990640.

The previous prime is 3990619. The next prime is 3990689. The reversal of 3990641 is 1460993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3500641 + 490000 = 1871^2 + 700^2 .

It is an emirp because it is prime and its reverse (1460993) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3990641 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 3990598 and 3990607.

It is not a weakly prime, because it can be changed into another prime (3990601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1995320 + 1995321.

It is an arithmetic number, because the mean of its divisors is an integer number (1995321).

Almost surely, 2^3990641 is an apocalyptic number.

It is an amenable number.

3990641 is a deficient number, since it is larger than the sum of its proper divisors (1).

3990641 is an equidigital number, since it uses as much as digits as its factorization.

3990641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 3990641 is about 1997.6588797890. The cubic root of 3990641 is about 158.6162044606.

The spelling of 3990641 in words is "three million, nine hundred ninety thousand, six hundred forty-one".