661105401 has 48 divisors (see below), whose sum is σ = 1034208000. Its totient is φ = 374049280.

The previous prime is 661105391. The next prime is 661105421. The reversal of 661105401 is 104501166.

It is not a de Polignac number, because 661105401 - 2⁷ = 661105273 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (661105421) 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 47 ways as a sum of consecutive naturals, for example, 919120 + ... + 919838.

It is an arithmetic number, because the mean of its divisors is an integer number (21546000).

Almost surely, 2^661105401 is an apocalyptic number.

It is an amenable number.

661105401 is a deficient number, since it is larger than the sum of its proper divisors (373102599).

661105401 is a wasteful number, since it uses less digits than its factorization.

661105401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910 (or 899 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 661105401 is about 25711.9699945376. The cubic root of 661105401 is about 871.1445722822.

Adding to 661105401 its reverse (104501166), we get a palindrome (765606567).

The spelling of 661105401 in words is "six hundred sixty-one million, one hundred five thousand, four hundred one".