661193995 has 48 divisors (see below), whose sum is σ = 1050755328. Its totient is φ = 394215360.

The previous prime is 661193987. The next prime is 661193999. The reversal of 661193995 is 599391166.

It is not a de Polignac number, because 661193995 - 2³ = 661193987 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (661193999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 56652 + ... + 67318.

It is an arithmetic number, because the mean of its divisors is an integer number (21890736).

Almost surely, 2^661193995 is an apocalyptic number.

661193995 is a deficient number, since it is larger than the sum of its proper divisors (389561333).

661193995 is a wasteful number, since it uses less digits than its factorization.

661193995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10720 (or 10713 counting only the distinct ones).

The product of its digits is 393660, while the sum is 49.

The square root of 661193995 is about 25713.6927530839. The cubic root of 661193995 is about 871.1834842494.

The spelling of 661193995 in words is "six hundred sixty-one million, one hundred ninety-three thousand, nine hundred ninety-five".