201561192520 has 32 divisors (see below), whose sum is σ = 455493108600. Its totient is φ = 80272401408.

The previous prime is 201561192509. The next prime is 201561192593. The reversal of 201561192520 is 25291165102.

It can be written as a sum of positive squares in 4 ways, for example, as 186169812676 + 15391379844 = 431474^2 + 124062^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10993089 + ... + 11011408.

Almost surely, 2^201561192520 is an apocalyptic number.

201561192520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201561192520 is an abundant number, since it is smaller than the sum of its proper divisors (253931916080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

201561192520 is a wasteful number, since it uses less digits than its factorization.

201561192520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22004737 (or 22004733 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 34.

The spelling of 201561192520 in words is "two hundred one billion, five hundred sixty-one million, one hundred ninety-two thousand, five hundred twenty".