19954991 has 16 divisors (see below), whose sum is σ = 24552000. Its totient is φ = 15828480.

The previous prime is 19954981. The next prime is 19955029. The reversal of 19954991 is 19945991.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 19954991 - 2⁶ = 19954927 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 (19954981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5885 + ... + 8633.

It is an arithmetic number, because the mean of its divisors is an integer number (1534500).

Almost surely, 2^19954991 is an apocalyptic number.

19954991 is a deficient number, since it is larger than the sum of its proper divisors (4597009).

19954991 is a wasteful number, since it uses less digits than its factorization.

19954991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2834.

The product of its digits is 131220, while the sum is 47.

The square root of 19954991 is about 4467.1009614738. The cubic root of 19954991 is about 271.2379866837.

The spelling of 19954991 in words is "nineteen million, nine hundred fifty-four thousand, nine hundred ninety-one".