20001689 has 4 divisors (see below), whose sum is σ = 20102400. Its totient is φ = 19900980.

The previous prime is 20001679. The next prime is 20001703. The reversal of 20001689 is 98610002.

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 20001689 - 2¹⁶ = 19936153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20001659) 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, 50057 + ... + 50454.

It is an arithmetic number, because the mean of its divisors is an integer number (5025600).

Almost surely, 2^20001689 is an apocalyptic number.

It is an amenable number.

20001689 is a deficient number, since it is larger than the sum of its proper divisors (100711).

20001689 is a wasteful number, since it uses less digits than its factorization.

20001689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100710.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 20001689 is about 4472.3247869536. The cubic root of 20001689 is about 271.4494025300.

The spelling of 20001689 in words is "twenty million, one thousand, six hundred eighty-nine".