20926181 has 2 divisors, whose sum is σ = 20926182. Its totient is φ = 20926180.

The previous prime is 20926153. The next prime is 20926187. The reversal of 20926181 is 18162902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14212900 + 6713281 = 3770^2 + 2591^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20926181 is a prime.

It is a super-2 number, since 2×20926181² = 875810102489522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20926187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10463090 + 10463091.

It is an arithmetic number, because the mean of its divisors is an integer number (10463091).

Almost surely, 2^20926181 is an apocalyptic number.

It is an amenable number.

20926181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20926181 is an equidigital number, since it uses as much as digits as its factorization.

20926181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 20926181 is about 4574.5142911570. The cubic root of 20926181 is about 275.5687666434.

The spelling of 20926181 in words is "twenty million, nine hundred twenty-six thousand, one hundred eighty-one".