20779489 has 2 divisors, whose sum is σ = 20779490. Its totient is φ = 20779488.

The previous prime is 20779477. The next prime is 20779531. The reversal of 20779489 is 98497702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16646400 + 4133089 = 4080^2 + 2033^2 .

It is a cyclic number.

It is not a de Polignac number, because 20779489 - 2⁷ = 20779361 is a prime.

It is a super-2 number, since 2×20779489² = 863574326202242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20779469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10389744 + 10389745.

It is an arithmetic number, because the mean of its divisors is an integer number (10389745).

Almost surely, 2^20779489 is an apocalyptic number.

It is an amenable number.

20779489 is a deficient number, since it is larger than the sum of its proper divisors (1).

20779489 is an equidigital number, since it uses as much as digits as its factorization.

20779489 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 254016, while the sum is 46.

The square root of 20779489 is about 4558.4524786379. The cubic root of 20779489 is about 274.9233461285.

The spelling of 20779489 in words is "twenty million, seven hundred seventy-nine thousand, four hundred eighty-nine".