188000281621 has 2 divisors, whose sum is σ = 188000281622. Its totient is φ = 188000281620.

The previous prime is 188000281613. The next prime is 188000281631. The reversal of 188000281621 is 126182000881.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 179988062500 + 8012219121 = 424250^2 + 89511^2 .

It is a cyclic number.

It is not a de Polignac number, because 188000281621 - 2³ = 188000281613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (188000281631) 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 as a sum of consecutive naturals, namely, 94000140810 + 94000140811.

It is an arithmetic number, because the mean of its divisors is an integer number (94000140811).

Almost surely, 2^188000281621 is an apocalyptic number.

It is an amenable number.

188000281621 is a deficient number, since it is larger than the sum of its proper divisors (1).

188000281621 is an equidigital number, since it uses as much as digits as its factorization.

188000281621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12288, while the sum is 37.

The spelling of 188000281621 in words is "one hundred eighty-eight billion, two hundred eighty-one thousand, six hundred twenty-one".