199540023 has 4 divisors (see below), whose sum is σ = 266053368. Its totient is φ = 133026680.

The previous prime is 199540021. The next prime is 199540027. The reversal of 199540023 is 320045991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 320045991 = 3 ⋅106681997.

It is a cyclic number.

It is not a de Polignac number, because 199540023 - 2¹ = 199540021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199540021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33256668 + ... + 33256673.

It is an arithmetic number, because the mean of its divisors is an integer number (66513342).

Almost surely, 2^199540023 is an apocalyptic number.

199540023 is a deficient number, since it is larger than the sum of its proper divisors (66513345).

199540023 is an equidigital number, since it uses as much as digits as its factorization.

199540023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66513344.

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 199540023 is about 14125.8636196163. The cubic root of 199540023 is about 584.3548765335.

The spelling of 199540023 in words is "one hundred ninety-nine million, five hundred forty thousand, twenty-three".