661366446765 has 16 divisors (see below), whose sum is σ = 1065288240000. Its totient is φ = 350361463232.

The previous prime is 661366446757. The next prime is 661366446773. The reversal of 661366446765 is 567644663166.

It is an interprime number because it is at equal distance from previous prime (661366446757) and next prime (661366446773).

It is a cyclic number.

It is not a de Polignac number, because 661366446765 - 2³ = 661366446757 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 661366446699 and 661366446708.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 147954465 + ... + 147958934.

It is an arithmetic number, because the mean of its divisors is an integer number (66580515000).

Almost surely, 2^661366446765 is an apocalyptic number.

It is an amenable number.

661366446765 is a deficient number, since it is larger than the sum of its proper divisors (403921793235).

661366446765 is a wasteful number, since it uses less digits than its factorization.

661366446765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295913556.

The product of its digits is 78382080, while the sum is 60.

The spelling of 661366446765 in words is "six hundred sixty-one billion, three hundred sixty-six million, four hundred forty-six thousand, seven hundred sixty-five".