20191001 has 4 divisors (see below), whose sum is σ = 20336400. Its totient is φ = 20045604.

The previous prime is 20190943. The next prime is 20191009. The reversal of 20191001 is 10019102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20191001 - 2¹⁴ = 20174617 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20191009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72491 + ... + 72768.

It is an arithmetic number, because the mean of its divisors is an integer number (5084100).

Almost surely, 2^20191001 is an apocalyptic number.

It is an amenable number.

20191001 is a deficient number, since it is larger than the sum of its proper divisors (145399).

20191001 is a wasteful number, since it uses less digits than its factorization.

20191001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145398.

The product of its (nonzero) digits is 18, while the sum is 14.

The square root of 20191001 is about 4493.4397737146. The cubic root of 20191001 is about 272.3031195793.

The spelling of 20191001 in words is "twenty million, one hundred ninety-one thousand, one".