120643665 has 32 divisors (see below), whose sum is σ = 198796800. Its totient is φ = 62449920.

The previous prime is 120643637. The next prime is 120643693. The reversal of 120643665 is 566346021.

It is an interprime number because it is at equal distance from previous prime (120643637) and next prime (120643693).

It is not a de Polignac number, because 120643665 - 2⁸ = 120643409 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 71451 + ... + 73119.

It is an arithmetic number, because the mean of its divisors is an integer number (6212400).

Almost surely, 2^120643665 is an apocalyptic number.

120643665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

120643665 is a deficient number, since it is larger than the sum of its proper divisors (78153135).

120643665 is a wasteful number, since it uses less digits than its factorization.

120643665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1817.

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 120643665 is about 10983.7910122143. The cubic root of 120643665 is about 494.1227396392.

Adding to 120643665 its reverse (566346021), we get a palindrome (686989686).

The spelling of 120643665 in words is "one hundred twenty million, six hundred forty-three thousand, six hundred sixty-five".