1187445881 has 2 divisors, whose sum is σ = 1187445882. Its totient is φ = 1187445880.

The previous prime is 1187445851. The next prime is 1187445887. The reversal of 1187445881 is 1885447811.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 866713600 + 320732281 = 29440^2 + 17909^2 .

It is a cyclic number.

It is not a de Polignac number, because 1187445881 - 2¹⁴ = 1187429497 is a prime.

It is a super-2 number, since 2×1187445881² = 2820055440607732322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1187445887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 593722940 + 593722941.

It is an arithmetic number, because the mean of its divisors is an integer number (593722941).

Almost surely, 2^1187445881 is an apocalyptic number.

It is an amenable number.

1187445881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1187445881 is an equidigital number, since it uses as much as digits as its factorization.

1187445881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 286720, while the sum is 47.

The square root of 1187445881 is about 34459.3366302951. The cubic root of 1187445881 is about 1058.9398089045.

The spelling of 1187445881 in words is "one billion, one hundred eighty-seven million, four hundred forty-five thousand, eight hundred eighty-one".