19949991 has 8 divisors (see below), whose sum is σ = 26622960. Its totient is φ = 13288512.

The previous prime is 19949977. The next prime is 19950013. The reversal of 19949991 is 19994991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19949991 - 2⁷ = 19949863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19949911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2761 + ... + 6893.

It is an arithmetic number, because the mean of its divisors is an integer number (3327870).

Almost surely, 2^19949991 is an apocalyptic number.

19949991 is a deficient number, since it is larger than the sum of its proper divisors (6672969).

19949991 is a wasteful number, since it uses less digits than its factorization.

19949991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5745.

The product of its digits is 236196, while the sum is 51.

The square root of 19949991 is about 4466.5412793346. The cubic root of 19949991 is about 271.2153306437.

The spelling of 19949991 in words is "nineteen million, nine hundred forty-nine thousand, nine hundred ninety-one".