1971667 has 2 divisors, whose sum is σ = 1971668. Its totient is φ = 1971666.

The previous prime is 1971659. The next prime is 1971691. The reversal of 1971667 is 7661791.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1971667 - 2³ = 1971659 is a prime.

It is not a weakly prime, because it can be changed into another prime (1971637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 985833 + 985834.

It is an arithmetic number, because the mean of its divisors is an integer number (985834).

2^1971667 is an apocalyptic number.

1971667 is a deficient number, since it is larger than the sum of its proper divisors (1).

1971667 is an equidigital number, since it uses as much as digits as its factorization.

1971667 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15876, while the sum is 37.

The square root of 1971667 is about 1404.1606033499. The cubic root of 1971667 is about 125.3943174686.

The spelling of 1971667 in words is "one million, nine hundred seventy-one thousand, six hundred sixty-seven".