120173781561 has 8 divisors (see below), whose sum is σ = 160233316704. Its totient is φ = 80115050400.

The previous prime is 120173781557. The next prime is 120173781571. The reversal of 120173781561 is 165187371021.

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

It is not a de Polignac number, because 120173781561 - 2² = 120173781557 is a prime.

It is a super-3 number, since 3×120173781561³ (a number of 34 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (120173781571) 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, 437886 + ... + 657336.

It is an arithmetic number, because the mean of its divisors is an integer number (20029164588).

Almost surely, 2^120173781561 is an apocalyptic number.

It is an amenable number.

120173781561 is a deficient number, since it is larger than the sum of its proper divisors (40059535143).

120173781561 is a wasteful number, since it uses less digits than its factorization.

120173781561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401991.

The product of its (nonzero) digits is 70560, while the sum is 42.

The spelling of 120173781561 in words is "one hundred twenty billion, one hundred seventy-three million, seven hundred eighty-one thousand, five hundred sixty-one".