20979229277 has 2 divisors, whose sum is σ = 20979229278. Its totient is φ = 20979229276.

The previous prime is 20979229217. The next prime is 20979229291. The reversal of 20979229277 is 77292297902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18319351801 + 2659877476 = 135349^2 + 51574^2 .

It is a cyclic number.

It is not a de Polignac number, because 20979229277 - 2¹⁶ = 20979163741 is a prime.

It is a super-2 number, since 2×20979229277² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20979229207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10489614638 + 10489614639.

It is an arithmetic number, because the mean of its divisors is an integer number (10489614639).

Almost surely, 2^20979229277 is an apocalyptic number.

It is an amenable number.

20979229277 is a deficient number, since it is larger than the sum of its proper divisors (1).

20979229277 is an equidigital number, since it uses as much as digits as its factorization.

20979229277 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4000752, while the sum is 56.

The spelling of 20979229277 in words is "twenty billion, nine hundred seventy-nine million, two hundred twenty-nine thousand, two hundred seventy-seven".