20918771 has 2 divisors, whose sum is σ = 20918772. Its totient is φ = 20918770.

The previous prime is 20918767. The next prime is 20918783. The reversal of 20918771 is 17781902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20918771 - 2² = 20918767 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20918701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10459385 + 10459386.

It is an arithmetic number, because the mean of its divisors is an integer number (10459386).

Almost surely, 2^20918771 is an apocalyptic number.

20918771 is a deficient number, since it is larger than the sum of its proper divisors (1).

20918771 is an equidigital number, since it uses as much as digits as its factorization.

20918771 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 35.

The square root of 20918771 is about 4573.7042973940. The cubic root of 20918771 is about 275.5362363308.

The spelling of 20918771 in words is "twenty million, nine hundred eighteen thousand, seven hundred seventy-one".