19795991 has 4 divisors (see below), whose sum is σ = 19929000. Its totient is φ = 19662984.

The previous prime is 19795987. The next prime is 19796017. The reversal of 19795991 is 19959791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19959791 = 23 ⋅867817.

It is a cyclic number.

It is not a de Polignac number, because 19795991 - 2² = 19795987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19795901) 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, 66281 + ... + 66578.

It is an arithmetic number, because the mean of its divisors is an integer number (4982250).

Almost surely, 2^19795991 is an apocalyptic number.

19795991 is a deficient number, since it is larger than the sum of its proper divisors (133009).

19795991 is a wasteful number, since it uses less digits than its factorization.

19795991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133008.

The product of its digits is 229635, while the sum is 50.

The square root of 19795991 is about 4449.2685915777. The cubic root of 19795991 is about 270.5156629045.

The spelling of 19795991 in words is "nineteen million, seven hundred ninety-five thousand, nine hundred ninety-one".