661645595 has 8 divisors (see below), whose sum is σ = 855049776. Its totient is φ = 488599776.

The previous prime is 661645573. The next prime is 661645597. The reversal of 661645595 is 595546166.

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 661645595 - 2⁸ = 661645339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661645597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5089517 + ... + 5089646.

It is an arithmetic number, because the mean of its divisors is an integer number (106881222).

Almost surely, 2^661645595 is an apocalyptic number.

661645595 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

661645595 is a deficient number, since it is larger than the sum of its proper divisors (193404181).

661645595 is a wasteful number, since it uses less digits than its factorization.

661645595 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10179181.

The product of its digits is 972000, while the sum is 47.

The square root of 661645595 is about 25722.4725677762. The cubic root of 661645595 is about 871.3817805273.

The spelling of 661645595 in words is "six hundred sixty-one million, six hundred forty-five thousand, five hundred ninety-five".