20378989 has 4 divisors (see below), whose sum is σ = 21265056. Its totient is φ = 19492924.

The previous prime is 20378957. The next prime is 20378999. The reversal of 20378989 is 98987302.

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 20378989 - 2⁵ = 20378957 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 (20378999) 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, 442999 + ... + 443044.

It is an arithmetic number, because the mean of its divisors is an integer number (5316264).

Almost surely, 2^20378989 is an apocalyptic number.

It is an amenable number.

20378989 is a deficient number, since it is larger than the sum of its proper divisors (886067).

20378989 is an equidigital number, since it uses as much as digits as its factorization.

20378989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 886066.

The product of its (nonzero) digits is 217728, while the sum is 46.

The square root of 20378989 is about 4514.3093602455. The cubic root of 20378989 is about 273.1456016416.

It can be divided in two parts, 2037 and 8989, that added together give a triangular number (11026 = T₁₄₈).

The spelling of 20378989 in words is "twenty million, three hundred seventy-eight thousand, nine hundred eighty-nine".