102120665 has 24 divisors (see below), whose sum is σ = 129336264. Its totient is φ = 77376000.

The previous prime is 102120661. The next prime is 102120671. The reversal of 102120665 is 566021201.

It can be written as a sum of positive squares in 4 ways, for example, as 50395801 + 51724864 = 7099^2 + 7192^2 .

It is not a de Polignac number, because 102120665 - 2² = 102120661 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 102120665.

It is not an unprimeable number, because it can be changed into a prime (102120661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 254465 + ... + 254865.

It is an arithmetic number, because the mean of its divisors is an integer number (5389011).

Almost surely, 2^102120665 is an apocalyptic number.

It is an amenable number.

102120665 is a deficient number, since it is larger than the sum of its proper divisors (27215599).

102120665 is an equidigital number, since it uses as much as digits as its factorization.

102120665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521 (or 490 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 102120665 is about 10105.4769803310. The cubic root of 102120665 is about 467.4170441996.

Adding to 102120665 its reverse (566021201), we get a palindrome (668141866).

The spelling of 102120665 in words is "one hundred two million, one hundred twenty thousand, six hundred sixty-five".