19144991 has 4 divisors (see below), whose sum is σ = 19611984. Its totient is φ = 18678000.

The previous prime is 19144981. The next prime is 19144997. The reversal of 19144991 is 19944191.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19144991 - 2²² = 14950687 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 (19144997) 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, 233435 + ... + 233516.

It is an arithmetic number, because the mean of its divisors is an integer number (4902996).

Almost surely, 2^19144991 is an apocalyptic number.

19144991 is a deficient number, since it is larger than the sum of its proper divisors (466993).

19144991 is an equidigital number, since it uses as much as digits as its factorization.

19144991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466992.

The product of its digits is 11664, while the sum is 38.

The square root of 19144991 is about 4375.4989429778. The cubic root of 19144991 is about 267.5172073829.

The spelling of 19144991 in words is "nineteen million, one hundred forty-four thousand, nine hundred ninety-one".