1187731157 has 4 divisors (see below), whose sum is σ = 1187890476. Its totient is φ = 1187571840.

The previous prime is 1187731133. The next prime is 1187731159. The reversal of 1187731157 is 7511377811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7511377811 = 7 ⋅1073053973.

It can be written as a sum of positive squares in 2 ways, for example, as 231313681 + 956417476 = 15209^2 + 30926^2 .

It is a cyclic number.

It is not a de Polignac number, because 1187731157 - 2⁶ = 1187731093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1187731159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67898 + ... + 83579.

It is an arithmetic number, because the mean of its divisors is an integer number (296972619).

Almost surely, 2^1187731157 is an apocalyptic number.

It is an amenable number.

1187731157 is a deficient number, since it is larger than the sum of its proper divisors (159319).

1187731157 is an equidigital number, since it uses as much as digits as its factorization.

1187731157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159318.

The product of its digits is 41160, while the sum is 41.

The square root of 1187731157 is about 34463.4756952923. The cubic root of 1187731157 is about 1059.0246032038.

It can be divided in two parts, 11877 and 31157, that added together give a palindrome (43034).

The spelling of 1187731157 in words is "one billion, one hundred eighty-seven million, seven hundred thirty-one thousand, one hundred fifty-seven".