661065145207 has 4 divisors (see below), whose sum is σ = 677188685376. Its totient is φ = 644941605040.

The previous prime is 661065145127. The next prime is 661065145217. The reversal of 661065145207 is 702541560166.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 661065145207 - 2¹¹ = 661065143159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661065145217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8061770023 + ... + 8061770104.

It is an arithmetic number, because the mean of its divisors is an integer number (169297171344).

Almost surely, 2^661065145207 is an apocalyptic number.

661065145207 is a deficient number, since it is larger than the sum of its proper divisors (16123540169).

661065145207 is a wasteful number, since it uses less digits than its factorization.

661065145207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16123540168.

The product of its (nonzero) digits is 302400, while the sum is 43.

The spelling of 661065145207 in words is "six hundred sixty-one billion, sixty-five million, one hundred forty-five thousand, two hundred seven".