1987693 has 2 divisors, whose sum is σ = 1987694. Its totient is φ = 1987692.

The previous prime is 1987681. The next prime is 1987697. The reversal of 1987693 is 3967891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1671849 + 315844 = 1293^2 + 562^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1987693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1987697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 993846 + 993847.

It is an arithmetic number, because the mean of its divisors is an integer number (993847).

2^1987693 is an apocalyptic number.

It is an amenable number.

1987693 is a deficient number, since it is larger than the sum of its proper divisors (1).

1987693 is an equidigital number, since it uses as much as digits as its factorization.

1987693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 43.

The square root of 1987693 is about 1409.8556663716. The cubic root of 1987693 is about 125.7331422792.

The spelling of 1987693 in words is "one million, nine hundred eighty-seven thousand, six hundred ninety-three".