201561512170 has 8 divisors (see below), whose sum is σ = 362810721924. Its totient is φ = 80624604864.

The previous prime is 201561512143. The next prime is 201561512171. The reversal of 201561512170 is 71215165102.

It can be written as a sum of positive squares in 2 ways, for example, as 201196205401 + 365306769 = 448549^2 + 19113^2 .

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

It is a super-3 number, since 3×201561512170³ (a number of 35 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (201561512171) 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, 10078075599 + ... + 10078075618.

Almost surely, 2^201561512170 is an apocalyptic number.

201561512170 is a deficient number, since it is larger than the sum of its proper divisors (161249209754).

201561512170 is a wasteful number, since it uses less digits than its factorization.

201561512170 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20156151224.

The product of its (nonzero) digits is 4200, while the sum is 31.

Adding to 201561512170 its reverse (71215165102), we get a palindrome (272776677272).

The spelling of 201561512170 in words is "two hundred one billion, five hundred sixty-one million, five hundred twelve thousand, one hundred seventy".