3991061 has 4 divisors (see below), whose sum is σ = 4008000. Its totient is φ = 3974124.

The previous prime is 3991051. The next prime is 3991087. The reversal of 3991061 is 1601993.

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.

It is a cyclic number.

It is not a de Polignac number, because 3991061 - 2⁶ = 3990997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991021) 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, 8111 + ... + 8588.

It is an arithmetic number, because the mean of its divisors is an integer number (1002000).

Almost surely, 2^3991061 is an apocalyptic number.

It is an amenable number.

3991061 is a deficient number, since it is larger than the sum of its proper divisors (16939).

3991061 is a wasteful number, since it uses less digits than its factorization.

3991061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16938.

The product of its (nonzero) digits is 1458, while the sum is 29.

The square root of 3991061 is about 1997.7640000761. The cubic root of 3991061 is about 158.6217688522.

The spelling of 3991061 in words is "three million, nine hundred ninety-one thousand, sixty-one".