20777489 has 2 divisors, whose sum is σ = 20777490. Its totient is φ = 20777488.

The previous prime is 20777483. The next prime is 20777501. The reversal of 20777489 is 98477702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18421264 + 2356225 = 4292^2 + 1535^2 .

It is a cyclic number.

It is not a de Polignac number, because 20777489 - 2²⁴ = 4000273 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20777483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10388744 + 10388745.

It is an arithmetic number, because the mean of its divisors is an integer number (10388745).

Almost surely, 2^20777489 is an apocalyptic number.

It is an amenable number.

20777489 is a deficient number, since it is larger than the sum of its proper divisors (1).

20777489 is an equidigital number, since it uses as much as digits as its factorization.

20777489 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 197568, while the sum is 44.

The square root of 20777489 is about 4558.2331006652. The cubic root of 20777489 is about 274.9145255020.

The spelling of 20777489 in words is "twenty million, seven hundred seventy-seven thousand, four hundred eighty-nine".