661511101670 has 16 divisors (see below), whose sum is σ = 1207490688288. Its totient is φ = 260877617280.

The previous prime is 661511101661. The next prime is 661511101679. The reversal of 661511101670 is 76101115166.

It is an interprime number because it is at equal distance from previous prime (661511101661) and next prime (661511101679).

It is a super-4 number, since 4×661511101670⁴ (a number of 48 digits) contains 4444 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 661511101670.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661511101679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 465852179 + ... + 465853598.

It is an arithmetic number, because the mean of its divisors is an integer number (75468168018).

Almost surely, 2^661511101670 is an apocalyptic number.

661511101670 is a deficient number, since it is larger than the sum of its proper divisors (545979586618).

661511101670 is a wasteful number, since it uses less digits than its factorization.

661511101670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931705855.

The product of its (nonzero) digits is 7560, while the sum is 35.

The spelling of 661511101670 in words is "six hundred sixty-one billion, five hundred eleven million, one hundred one thousand, six hundred seventy".