665057961 has 12 divisors (see below), whose sum is σ = 966393792. Its totient is φ = 440716056.

The previous prime is 665057951. The next prime is 665057963. The reversal of 665057961 is 169750566.

It is not a de Polignac number, because 665057961 - 2¹³ = 665049769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (665057963) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 219741 + ... + 222746.

It is an arithmetic number, because the mean of its divisors is an integer number (80532816).

Almost surely, 2^665057961 is an apocalyptic number.

It is an amenable number.

665057961 is a deficient number, since it is larger than the sum of its proper divisors (301335831).

665057961 is a wasteful number, since it uses less digits than its factorization.

665057961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442660 (or 442657 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 45.

The square root of 665057961 is about 25788.7177075558. The cubic root of 665057961 is about 872.8772318633.

The spelling of 665057961 in words is "six hundred sixty-five million, fifty-seven thousand, nine hundred sixty-one".