3121691 has 2 divisors, whose sum is σ = 3121692. Its totient is φ = 3121690.

The previous prime is 3121667. The next prime is 3121711. The reversal of 3121691 is 1961213.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (1961213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3121691 - 2⁶ = 3121627 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (3121091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1560845 + 1560846.

It is an arithmetic number, because the mean of its divisors is an integer number (1560846).

Almost surely, 2^3121691 is an apocalyptic number.

3121691 is a deficient number, since it is larger than the sum of its proper divisors (1).

3121691 is an equidigital number, since it uses as much as digits as its factorization.

3121691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 324, while the sum is 23.

The square root of 3121691 is about 1766.8307785411. The cubic root of 3121691 is about 146.1492656211.

The spelling of 3121691 in words is "three million, one hundred twenty-one thousand, six hundred ninety-one".