20870777 has 2 divisors, whose sum is σ = 20870778. Its totient is φ = 20870776.

The previous prime is 20870753. The next prime is 20870779. The reversal of 20870777 is 77707802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11316496 + 9554281 = 3364^2 + 3091^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20870777 is a prime.

Together with 20870779, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20870777.

It is not a weakly prime, because it can be changed into another prime (20870779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10435388 + 10435389.

It is an arithmetic number, because the mean of its divisors is an integer number (10435389).

Almost surely, 2^20870777 is an apocalyptic number.

It is an amenable number.

20870777 is a deficient number, since it is larger than the sum of its proper divisors (1).

20870777 is an equidigital number, since it uses as much as digits as its factorization.

20870777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38416, while the sum is 38.

The square root of 20870777 is about 4568.4545526907. The cubic root of 20870777 is about 275.3253537636.

The spelling of 20870777 in words is "twenty million, eight hundred seventy thousand, seven hundred seventy-seven".