202115561 has 4 divisors (see below), whose sum is σ = 204077952. Its totient is φ = 200153172.

The previous prime is 202115549. The next prime is 202115581. The reversal of 202115561 is 165511202.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-202115561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (202115581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 981041 + ... + 981246.

It is an arithmetic number, because the mean of its divisors is an integer number (51019488).

Almost surely, 2^202115561 is an apocalyptic number.

It is an amenable number.

202115561 is a deficient number, since it is larger than the sum of its proper divisors (1962391).

202115561 is a wasteful number, since it uses less digits than its factorization.

202115561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1962390.

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 202115561 is about 14216.7352440706. The cubic root of 202115561 is about 586.8582989603.

Adding to 202115561 its reverse (165511202), we get a palindrome (367626763).

The spelling of 202115561 in words is "two hundred two million, one hundred fifteen thousand, five hundred sixty-one".