1187981051257 has 32 divisors (see below), whose sum is σ = 1608233889024. Its totient is φ = 854491777920.

The previous prime is 1187981051251. The next prime is 1187981051317. The reversal of 1187981051257 is 7521501897811.

It is a happy number.

It is not a de Polignac number, because 1187981051257 - 2¹¹ = 1187981049209 is a prime.

It is a super-2 number, since 2×1187981051257² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1187981051198 and 1187981051207.

It is not an unprimeable number, because it can be changed into a prime (1187981051251) 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 31 ways as a sum of consecutive naturals, for example, 4782988 + ... + 5025229.

It is an arithmetic number, because the mean of its divisors is an integer number (50257309032).

Almost surely, 2^{1187981051257} is an apocalyptic number.

It is an amenable number.

1187981051257 is a deficient number, since it is larger than the sum of its proper divisors (420252837767).

1187981051257 is an equidigital number, since it uses as much as digits as its factorization.

1187981051257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9808270 (or 9808248 counting only the distinct ones).

The product of its (nonzero) digits is 1411200, while the sum is 55.

The spelling of 1187981051257 in words is "one trillion, one hundred eighty-seven billion, nine hundred eighty-one million, fifty-one thousand, two hundred fifty-seven".