3991051 has 2 divisors, whose sum is σ = 3991052. Its totient is φ = 3991050.

The previous prime is 3991037. The next prime is 3991087. The reversal of 3991051 is 1501993.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3991051 - 2⁵ = 3991019 is a prime.

3991051 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (3991021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1995525 + 1995526.

It is an arithmetic number, because the mean of its divisors is an integer number (1995526).

Almost surely, 2^3991051 is an apocalyptic number.

3991051 is a deficient number, since it is larger than the sum of its proper divisors (1).

3991051 is an equidigital number, since it uses as much as digits as its factorization.

3991051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1215, while the sum is 28.

The square root of 3991051 is about 1997.7614972764. The cubic root of 3991051 is about 158.6216363713.

The spelling of 3991051 in words is "three million, nine hundred ninety-one thousand, fifty-one".