20879477 has 2 divisors, whose sum is σ = 20879478. Its totient is φ = 20879476.

The previous prime is 20879459. The next prime is 20879479. The reversal of 20879477 is 77497802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18541636 + 2337841 = 4306^2 + 1529^2 .

It is a cyclic number.

It is not a de Polignac number, because 20879477 - 2¹⁰ = 20878453 is a prime.

It is a super-4 number, since 4×20879477⁴ (a number of 30 digits) contains 4444 as substring.

Together with 20879479, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20879479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10439738 + 10439739.

It is an arithmetic number, because the mean of its divisors is an integer number (10439739).

Almost surely, 2^20879477 is an apocalyptic number.

It is an amenable number.

20879477 is a deficient number, since it is larger than the sum of its proper divisors (1).

20879477 is an equidigital number, since it uses as much as digits as its factorization.

20879477 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 20879477 is about 4569.4066354397. The cubic root of 20879477 is about 275.3636049800.

The spelling of 20879477 in words is "twenty million, eight hundred seventy-nine thousand, four hundred seventy-seven".