186993202399981 has 2 divisors, whose sum is σ = 186993202399982. Its totient is φ = 186993202399980.

The previous prime is 186993202399937. The next prime is 186993202400029. The reversal of 186993202399981 is 189993202399681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 184876369455625 + 2116832944356 = 13596925^2 + 1454934^2 .

It is a cyclic number.

It is not a de Polignac number, because 186993202399981 - 2³³ = 186984612465389 is a prime.

It is a super-2 number, since 2×186993202399981² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (186993202399931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93496601199990 + 93496601199991.

It is an arithmetic number, because the mean of its divisors is an integer number (93496601199991).

Almost surely, 2^{186993202399981} is an apocalyptic number.

It is an amenable number.

186993202399981 is a deficient number, since it is larger than the sum of its proper divisors (1).

186993202399981 is an equidigital number, since it uses as much as digits as its factorization.

186993202399981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 816293376, while the sum is 79.

The spelling of 186993202399981 in words is "one hundred eighty-six trillion, nine hundred ninety-three billion, two hundred two million, three hundred ninety-nine thousand, nine hundred eighty-one".