20910161 has 4 divisors (see below), whose sum is σ = 20919792. Its totient is φ = 20900532.

The previous prime is 20910157. The next prime is 20910163. The reversal of 20910161 is 16101902.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20910161 - 2² = 20910157 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20910163) 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, 146 + ... + 6468.

It is an arithmetic number, because the mean of its divisors is an integer number (5229948).

Almost surely, 2^20910161 is an apocalyptic number.

It is an amenable number.

20910161 is a deficient number, since it is larger than the sum of its proper divisors (9631).

20910161 is an equidigital number, since it uses as much as digits as its factorization.

20910161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9630.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 20910161 is about 4572.7629503398. The cubic root of 20910161 is about 275.4984283010.

The spelling of 20910161 in words is "twenty million, nine hundred ten thousand, one hundred sixty-one".