20128765 has 16 divisors (see below), whose sum is σ = 26403840. Its totient is φ = 14664960.

The previous prime is 20128763. The next prime is 20128781. The reversal of 20128765 is 56782102.

It is not a de Polignac number, because 20128765 - 2¹ = 20128763 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20128763) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1185 + ... + 6454.

It is an arithmetic number, because the mean of its divisors is an integer number (1650240).

Almost surely, 2^20128765 is an apocalyptic number.

It is an amenable number.

20128765 is a deficient number, since it is larger than the sum of its proper divisors (6275075).

20128765 is a wasteful number, since it uses less digits than its factorization.

20128765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7692.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 20128765 is about 4486.5092221013. The cubic root of 20128765 is about 272.0230525805.

The spelling of 20128765 in words is "twenty million, one hundred twenty-eight thousand, seven hundred sixty-five".