661326115416401 has 8 divisors (see below), whose sum is σ = 676726875765600. Its totient is φ = 645926313396672.

The previous prime is 661326115416397. The next prime is 661326115416497. The reversal of 661326115416401 is 104614511623166.

It is a happy number.

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 661326115416401 - 2² = 661326115416397 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661326115436401) 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, 238186040 + ... + 240946553.

It is an arithmetic number, because the mean of its divisors is an integer number (84590859470700).

Almost surely, 2^{661326115416401} is an apocalyptic number.

It is an amenable number.

661326115416401 is a deficient number, since it is larger than the sum of its proper divisors (15400760349199).

661326115416401 is a wasteful number, since it uses less digits than its factorization.

661326115416401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479164735.

The product of its (nonzero) digits is 622080, while the sum is 47.

The spelling of 661326115416401 in words is "six hundred sixty-one trillion, three hundred twenty-six billion, one hundred fifteen million, four hundred sixteen thousand, four hundred one".