661454606454165 has 48 divisors (see below), whose sum is σ = 1147776515458560. Its totient is φ = 352389636466560.

The previous prime is 661454606454157. The next prime is 661454606454179. The reversal of 661454606454165 is 561454606454166.

661454606454165 is a `hidden beast` number, since 6 + 6 + 1 + 4 + 5 + 4 + 606 + 4 + 5 + 4 + 16 + 5 = 666.

It is not a de Polignac number, because 661454606454165 - 2³ = 661454606454157 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 525101374 + ... + 526359536.

It is an arithmetic number, because the mean of its divisors is an integer number (23912010738720).

Almost surely, 2^{661454606454165} is an apocalyptic number.

It is an amenable number.

661454606454165 is a deficient number, since it is larger than the sum of its proper divisors (486321909004395).

661454606454165 is a wasteful number, since it uses less digits than its factorization.

661454606454165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1270954 (or 1270951 counting only the distinct ones).

The product of its (nonzero) digits is 248832000, while the sum is 63.

Subtracting from 661454606454165 its reverse (561454606454166), we obtain a palindrome (99999999999999).

The spelling of 661454606454165 in words is "six hundred sixty-one trillion, four hundred fifty-four billion, six hundred six million, four hundred fifty-four thousand, one hundred sixty-five".