1187457989 has 2 divisors, whose sum is σ = 1187457990. Its totient is φ = 1187457988.

The previous prime is 1187457977. The next prime is 1187458003. The reversal of 1187457989 is 9897547811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1103369089 + 84088900 = 33217^2 + 9170^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1187457989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1187450989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 593728994 + 593728995.

It is an arithmetic number, because the mean of its divisors is an integer number (593728995).

Almost surely, 2^1187457989 is an apocalyptic number.

It is an amenable number.

1187457989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1187457989 is an equidigital number, since it uses as much as digits as its factorization.

1187457989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5080320, while the sum is 59.

The square root of 1187457989 is about 34459.5123151794. The cubic root of 1187457989 is about 1058.9434081140.

The spelling of 1187457989 in words is "one billion, one hundred eighty-seven million, four hundred fifty-seven thousand, nine hundred eighty-nine".