661895461289 has 8 divisors (see below), whose sum is σ = 668397972480. Its totient is φ = 655417817136.

The previous prime is 661895461273. The next prime is 661895461291. The reversal of 661895461289 is 982164598166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 661895461289 - 2⁴ = 661895461273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661895461589) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6163262 + ... + 6269735.

It is an arithmetic number, because the mean of its divisors is an integer number (83549746560).

Almost surely, 2^661895461289 is an apocalyptic number.

It is an amenable number.

661895461289 is a deficient number, since it is larger than the sum of its proper divisors (6502511191).

661895461289 is a wasteful number, since it uses less digits than its factorization.

661895461289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12433519.

The product of its digits is 44789760, while the sum is 65.

The spelling of 661895461289 in words is "six hundred sixty-one billion, eight hundred ninety-five million, four hundred sixty-one thousand, two hundred eighty-nine".