11551787381 has 2 divisors, whose sum is σ = 11551787382. Its totient is φ = 11551787380.

The previous prime is 11551787347. The next prime is 11551787431. The reversal of 11551787381 is 18378715511.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8735893156 + 2815894225 = 93466^2 + 53065^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11551787381 is a prime.

It is a super-2 number, since 2×11551787381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11551787311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5775893690 + 5775893691.

It is an arithmetic number, because the mean of its divisors is an integer number (5775893691).

Almost surely, 2^11551787381 is an apocalyptic number.

It is an amenable number.

11551787381 is a deficient number, since it is larger than the sum of its proper divisors (1).

11551787381 is an equidigital number, since it uses as much as digits as its factorization.

11551787381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 235200, while the sum is 47.

The spelling of 11551787381 in words is "eleven billion, five hundred fifty-one million, seven hundred eighty-seven thousand, three hundred eighty-one".