20389975 has 6 divisors (see below), whose sum is σ = 25283600. Its totient is φ = 16311960.

The previous prime is 20389951. The next prime is 20389991. The reversal of 20389975 is 57998302.

It is a happy number.

It is not a de Polignac number, because 20389975 - 2⁹ = 20389463 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 407775 + ... + 407824.

Almost surely, 2^20389975 is an apocalyptic number.

20389975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20389975 is a deficient number, since it is larger than the sum of its proper divisors (4893625).

20389975 is an equidigital number, since it uses as much as digits as its factorization.

20389975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815609 (or 815604 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 43.

The square root of 20389975 is about 4515.5259937243. The cubic root of 20389975 is about 273.1946756907.

The spelling of 20389975 in words is "twenty million, three hundred eighty-nine thousand, nine hundred seventy-five".