20797771 has 2 divisors, whose sum is σ = 20797772. Its totient is φ = 20797770.

The previous prime is 20797769. The next prime is 20797789. The reversal of 20797771 is 17779702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20797771 - 2¹ = 20797769 is a prime.

Together with 20797769, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20797741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10398885 + 10398886.

It is an arithmetic number, because the mean of its divisors is an integer number (10398886).

Almost surely, 2^20797771 is an apocalyptic number.

20797771 is a deficient number, since it is larger than the sum of its proper divisors (1).

20797771 is an equidigital number, since it uses as much as digits as its factorization.

20797771 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43218, while the sum is 40.

The square root of 20797771 is about 4560.4573235587. The cubic root of 20797771 is about 275.0039492546.

The spelling of 20797771 in words is "twenty million, seven hundred ninety-seven thousand, seven hundred seventy-one".