20201125661 has 4 divisors (see below), whose sum is σ = 20290117632. Its totient is φ = 20112133692.

The previous prime is 20201125657. The next prime is 20201125673. The reversal of 20201125661 is 16652110202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20201125661 - 2² = 20201125657 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20201125661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20201125361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44495645 + ... + 44496098.

It is an arithmetic number, because the mean of its divisors is an integer number (5072529408).

Almost surely, 2^20201125661 is an apocalyptic number.

It is an amenable number.

20201125661 is a deficient number, since it is larger than the sum of its proper divisors (88991971).

20201125661 is an equidigital number, since it uses as much as digits as its factorization.

20201125661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88991970.

The product of its (nonzero) digits is 1440, while the sum is 26.

Adding to 20201125661 its reverse (16652110202), we get a palindrome (36853235863).

The spelling of 20201125661 in words is "twenty billion, two hundred one million, one hundred twenty-five thousand, six hundred sixty-one".