20978782373 has 2 divisors, whose sum is σ = 20978782374. Its totient is φ = 20978782372.

The previous prime is 20978782361. The next prime is 20978782411. The reversal of 20978782373 is 37328787902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20976597889 + 2184484 = 144833^2 + 1478^2 .

It is a cyclic number.

It is not a de Polignac number, because 20978782373 - 2⁶ = 20978782309 is a prime.

It is a super-2 number, since 2×20978782373² (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 (20978782343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10489391186 + 10489391187.

It is an arithmetic number, because the mean of its divisors is an integer number (10489391187).

Almost surely, 2^20978782373 is an apocalyptic number.

It is an amenable number.

20978782373 is a deficient number, since it is larger than the sum of its proper divisors (1).

20978782373 is an equidigital number, since it uses as much as digits as its factorization.

20978782373 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7112448, while the sum is 56.

The spelling of 20978782373 in words is "twenty billion, nine hundred seventy-eight million, seven hundred eighty-two thousand, three hundred seventy-three".