661376111 has 8 divisors (see below), whose sum is σ = 759475200. Its totient is φ = 569606040.

The previous prime is 661375951. The next prime is 661376113. The reversal of 661376111 is 111673166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661376111 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661376113) 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, 1582031 + ... + 1582448.

It is an arithmetic number, because the mean of its divisors is an integer number (94934400).

Almost surely, 2^661376111 is an apocalyptic number.

661376111 is a deficient number, since it is larger than the sum of its proper divisors (98099089).

661376111 is a wasteful number, since it uses less digits than its factorization.

661376111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3164509.

The product of its digits is 4536, while the sum is 32.

The square root of 661376111 is about 25717.2337353768. The cubic root of 661376111 is about 871.2634617287.

The spelling of 661376111 in words is "six hundred sixty-one million, three hundred seventy-six thousand, one hundred eleven".