661771670075 has 6 divisors (see below), whose sum is σ = 820596870924. Its totient is φ = 529417336040.

The previous prime is 661771670029. The next prime is 661771670111. The reversal of 661771670075 is 570076177166.

It is a happy number.

It is not a de Polignac number, because 661771670075 - 2¹⁰ = 661771669051 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661771669999 and 661771670026.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13235433377 + ... + 13235433426.

It is an arithmetic number, because the mean of its divisors is an integer number (136766145154).

Almost surely, 2^661771670075 is an apocalyptic number.

661771670075 is a deficient number, since it is larger than the sum of its proper divisors (158825200849).

661771670075 is a wasteful number, since it uses less digits than its factorization.

661771670075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26470866813 (or 26470866808 counting only the distinct ones).

The product of its (nonzero) digits is 2593080, while the sum is 53.

The spelling of 661771670075 in words is "six hundred sixty-one billion, seven hundred seventy-one million, six hundred seventy thousand, seventy-five".