199451887 has 2 divisors, whose sum is σ = 199451888. Its totient is φ = 199451886.

The previous prime is 199451843. The next prime is 199451947. The reversal of 199451887 is 788154991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199451887 - 2¹¹ = 199449839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199451807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99725943 + 99725944.

It is an arithmetic number, because the mean of its divisors is an integer number (99725944).

Almost surely, 2^199451887 is an apocalyptic number.

199451887 is a deficient number, since it is larger than the sum of its proper divisors (1).

199451887 is an equidigital number, since it uses as much as digits as its factorization.

199451887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 725760, while the sum is 52.

The square root of 199451887 is about 14122.7436073873. The cubic root of 199451887 is about 584.2688281553.

The spelling of 199451887 in words is "one hundred ninety-nine million, four hundred fifty-one thousand, eight hundred eighty-seven".