20780928265 has 16 divisors (see below), whose sum is σ = 26665439760. Its totient is φ = 15491891200.

The previous prime is 20780928253. The next prime is 20780928277. The reversal of 20780928265 is 56282908702.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20780928253) and next prime (20780928277).

It can be written as a sum of positive squares in 8 ways, for example, as 1538522176 + 19242406089 = 39224^2 + 138717^2 .

It is not a de Polignac number, because 20780928265 - 2⁷ = 20780928137 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1201720 + ... + 1218889.

It is an arithmetic number, because the mean of its divisors is an integer number (1666589985).

Almost surely, 2^20780928265 is an apocalyptic number.

It is an amenable number.

20780928265 is a deficient number, since it is larger than the sum of its proper divisors (5884511495).

20780928265 is a wasteful number, since it uses less digits than its factorization.

20780928265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2420732.

The product of its (nonzero) digits is 967680, while the sum is 49.

The spelling of 20780928265 in words is "twenty billion, seven hundred eighty million, nine hundred twenty-eight thousand, two hundred sixty-five".