3951691 has 4 divisors (see below), whose sum is σ = 3965472. Its totient is φ = 3937912.

The previous prime is 3951611. The next prime is 3951707. The reversal of 3951691 is 1961593.

3951691 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 3951691 - 2⁹ = 3951179 is a prime.

It is an Ulam number.

It is a Duffinian number.

3951691 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3951611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6451 + ... + 7036.

It is an arithmetic number, because the mean of its divisors is an integer number (991368).

Almost surely, 2^3951691 is an apocalyptic number.

3951691 is a deficient number, since it is larger than the sum of its proper divisors (13781).

3951691 is a wasteful number, since it uses less digits than its factorization.

3951691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13780.

The product of its digits is 7290, while the sum is 34.

The square root of 3951691 is about 1987.8860631334. The cubic root of 3951691 is about 158.0984671693.

The spelling of 3951691 in words is "three million, nine hundred fifty-one thousand, six hundred ninety-one".