201245121661 has 8 divisors (see below), whose sum is σ = 213564078144. Its totient is φ = 188979610560.

The previous prime is 201245121659. The next prime is 201245121673. The reversal of 201245121661 is 166121542102.

It is a happy number.

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

It is not a de Polignac number, because 201245121661 - 2¹ = 201245121659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201245121761) by changing a digit.

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, 13353585 + ... + 13368646.

It is an arithmetic number, because the mean of its divisors is an integer number (26695509768).

Almost surely, 2^201245121661 is an apocalyptic number.

It is an amenable number.

201245121661 is a deficient number, since it is larger than the sum of its proper divisors (12318956483).

201245121661 is a wasteful number, since it uses less digits than its factorization.

201245121661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26722691.

The product of its (nonzero) digits is 5760, while the sum is 31.

Adding to 201245121661 its reverse (166121542102), we get a palindrome (367366663763).

The spelling of 201245121661 in words is "two hundred one billion, two hundred forty-five million, one hundred twenty-one thousand, six hundred sixty-one".