188416381 has 2 divisors, whose sum is σ = 188416382. Its totient is φ = 188416380.

The previous prime is 188416337. The next prime is 188416399. The reversal of 188416381 is 183614881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121749156 + 66667225 = 11034^2 + 8165^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-188416381 is a prime.

It is a super-2 number, since 2×188416381² = 71001465258274322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (188416301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94208190 + 94208191.

It is an arithmetic number, because the mean of its divisors is an integer number (94208191).

Almost surely, 2^188416381 is an apocalyptic number.

It is an amenable number.

188416381 is a deficient number, since it is larger than the sum of its proper divisors (1).

188416381 is an equidigital number, since it uses as much as digits as its factorization.

188416381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36864, while the sum is 40.

The square root of 188416381 is about 13726.4846555846. The cubic root of 188416381 is about 573.2880457813.

The spelling of 188416381 in words is "one hundred eighty-eight million, four hundred sixteen thousand, three hundred eighty-one".