1011811987 has 2 divisors, whose sum is σ = 1011811988. Its totient is φ = 1011811986.

The previous prime is 1011811961. The next prime is 1011812017. The reversal of 1011811987 is 7891181101.

It is a happy number.

1011811987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (7891181101) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1011811987 is a prime.

It is not a weakly prime, because it can be changed into another prime (1011811907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 505905993 + 505905994.

It is an arithmetic number, because the mean of its divisors is an integer number (505905994).

Almost surely, 2^1011811987 is an apocalyptic number.

1011811987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1011811987 is an equidigital number, since it uses as much as digits as its factorization.

1011811987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 37.

The square root of 1011811987 is about 31808.9922349011. The cubic root of 1011811987 is about 1003.9219273773.

The spelling of 1011811987 in words is "one billion, eleven million, eight hundred eleven thousand, nine hundred eighty-seven".