1020500665 has 8 divisors (see below), whose sum is σ = 1228465800. Its totient is φ = 813823872.

The previous prime is 1020500647. The next prime is 1020500669. The reversal of 1020500665 is 5660050201.

It can be written as a sum of positive squares in 4 ways, for example, as 40309801 + 980190864 = 6349^2 + 31308^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1020500665 - 2¹⁵ = 1020467897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1020500669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 320340 + ... + 323509.

It is an arithmetic number, because the mean of its divisors is an integer number (153558225).

Almost surely, 2^1020500665 is an apocalyptic number.

It is an amenable number.

1020500665 is a deficient number, since it is larger than the sum of its proper divisors (207965135).

1020500665 is an equidigital number, since it uses as much as digits as its factorization.

1020500665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644171.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 1020500665 is about 31945.2760983529. The cubic root of 1020500665 is about 1006.7873822144.

Adding to 1020500665 its reverse (5660050201), we get a palindrome (6680550866).

The spelling of 1020500665 in words is "one billion, twenty million, five hundred thousand, six hundred sixty-five".