20988251077 has 2 divisors, whose sum is σ = 20988251078. Its totient is φ = 20988251076.

The previous prime is 20988251033. The next prime is 20988251087. The reversal of 20988251077 is 77015288902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20967329601 + 20921476 = 144801^2 + 4574^2 .

It is a cyclic number.

It is not a de Polignac number, because 20988251077 - 2¹⁹ = 20987726789 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20988251077.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20988251087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10494125538 + 10494125539.

It is an arithmetic number, because the mean of its divisors is an integer number (10494125539).

Almost surely, 2^20988251077 is an apocalyptic number.

It is an amenable number.

20988251077 is a deficient number, since it is larger than the sum of its proper divisors (1).

20988251077 is an equidigital number, since it uses as much as digits as its factorization.

20988251077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 564480, while the sum is 49.

It can be divided in two parts, 2098825 and 1077, that added together give a palindrome (2099902).

The spelling of 20988251077 in words is "twenty billion, nine hundred eighty-eight million, two hundred fifty-one thousand, seventy-seven".