11111321987 has 2 divisors, whose sum is σ = 11111321988. Its totient is φ = 11111321986.

The previous prime is 11111321983. The next prime is 11111322023. The reversal of 11111321987 is 78912311111.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11111321987 - 2² = 11111321983 is a prime.

It is a super-2 number, since 2×11111321987² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (11111321983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5555660993 + 5555660994.

It is an arithmetic number, because the mean of its divisors is an integer number (5555660994).

Almost surely, 2^11111321987 is an apocalyptic number.

11111321987 is a deficient number, since it is larger than the sum of its proper divisors (1).

11111321987 is an equidigital number, since it uses as much as digits as its factorization.

11111321987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 35.

The spelling of 11111321987 in words is "eleven billion, one hundred eleven million, three hundred twenty-one thousand, nine hundred eighty-seven".