3961861 has 4 divisors (see below), whose sum is σ = 4170400. Its totient is φ = 3753324.

The previous prime is 3961847. The next prime is 3961877. The reversal of 3961861 is 1681693.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1681693 = 13 ⋅129361.

It is a cyclic number.

It is not a de Polignac number, because 3961861 - 2¹³ = 3953669 is a prime.

It is a Duffinian number.

3961861 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3961261) 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, 104241 + ... + 104278.

It is an arithmetic number, because the mean of its divisors is an integer number (1042600).

Almost surely, 2^3961861 is an apocalyptic number.

It is an amenable number.

3961861 is a deficient number, since it is larger than the sum of its proper divisors (208539).

3961861 is a wasteful number, since it uses less digits than its factorization.

3961861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208538.

The product of its digits is 7776, while the sum is 34.

The square root of 3961861 is about 1990.4424131333. The cubic root of 3961861 is about 158.2339774322.

The spelling of 3961861 in words is "three million, nine hundred sixty-one thousand, eight hundred sixty-one".