1978567 has 2 divisors, whose sum is σ = 1978568. Its totient is φ = 1978566.

The previous prime is 1978541. The next prime is 1978589. The reversal of 1978567 is 7658791.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1978567 - 2⁷ = 1978439 is a prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1978507) 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 as a sum of consecutive naturals, namely, 989283 + 989284.

It is an arithmetic number, because the mean of its divisors is an integer number (989284).

2^1978567 is an apocalyptic number.

1978567 is a deficient number, since it is larger than the sum of its proper divisors (1).

1978567 is an equidigital number, since it uses as much as digits as its factorization.

1978567 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 105840, while the sum is 43.

The square root of 1978567 is about 1406.6154414054. The cubic root of 1978567 is about 125.5404228447.

The spelling of 1978567 in words is "one million, nine hundred seventy-eight thousand, five hundred sixty-seven".