3959781 has 16 divisors (see below), whose sum is σ = 6071424. Its totient is φ = 2248704.

The previous prime is 3959729. The next prime is 3959801. The reversal of 3959781 is 1879593.

It is a happy number.

It is not a de Polignac number, because 3959781 - 2⁷ = 3959653 is a prime.

It is a super-2 number, since 2×3959781² = 31359731135922, which contains 22 as substring.

It is a Curzon number.

3959781 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3959701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3565 + ... + 4541.

It is an arithmetic number, because the mean of its divisors is an integer number (379464).

Almost surely, 2^3959781 is an apocalyptic number.

It is an amenable number.

3959781 is a deficient number, since it is larger than the sum of its proper divisors (2111643).

3959781 is a wasteful number, since it uses less digits than its factorization.

3959781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1180.

The product of its digits is 68040, while the sum is 42.

The square root of 3959781 is about 1989.9198476321. The cubic root of 3959781 is about 158.2062813329.

The spelling of 3959781 in words is "three million, nine hundred fifty-nine thousand, seven hundred eighty-one".