20121331187 has 2 divisors, whose sum is σ = 20121331188. Its totient is φ = 20121331186.

The previous prime is 20121331141. The next prime is 20121331207. The reversal of 20121331187 is 78113312102.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20121331187 is a prime.

It is not a weakly prime, because it can be changed into another prime (20121331117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060665593 + 10060665594.

It is an arithmetic number, because the mean of its divisors is an integer number (10060665594).

Almost surely, 2^20121331187 is an apocalyptic number.

20121331187 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121331187 is an equidigital number, since it uses as much as digits as its factorization.

20121331187 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 29.

Adding to 20121331187 its reverse (78113312102), we get a palindrome (98234643289).

The spelling of 20121331187 in words is "twenty billion, one hundred twenty-one million, three hundred thirty-one thousand, one hundred eighty-seven".