20561101 has 4 divisors (see below), whose sum is σ = 22430304. Its totient is φ = 18691900.

The previous prime is 20561083. The next prime is 20561111. The reversal of 20561101 is 10116502.

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 not a de Polignac number, because 20561101 - 2⁵ = 20561069 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20561111) 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, 934585 + ... + 934606.

It is an arithmetic number, because the mean of its divisors is an integer number (5607576).

Almost surely, 2^20561101 is an apocalyptic number.

It is an amenable number.

20561101 is a deficient number, since it is larger than the sum of its proper divisors (1869203).

20561101 is a wasteful number, since it uses less digits than its factorization.

20561101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1869202.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 20561101 is about 4534.4350254469. The cubic root of 20561101 is about 273.9568236086.

Adding to 20561101 its reverse (10116502), we get a palindrome (30677603).

The spelling of 20561101 in words is "twenty million, five hundred sixty-one thousand, one hundred one".