19781632373 has 2 divisors, whose sum is σ = 19781632374. Its totient is φ = 19781632372.

The previous prime is 19781632357. The next prime is 19781632397. The reversal of 19781632373 is 37323618791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17190618769 + 2591013604 = 131113^2 + 50902^2 .

It is a cyclic number.

It is not a de Polignac number, because 19781632373 - 2⁴ = 19781632357 is a prime.

It is a super-2 number, since 2×19781632373² (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 (19781632313) 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, 9890816186 + 9890816187.

It is an arithmetic number, because the mean of its divisors is an integer number (9890816187).

Almost surely, 2^19781632373 is an apocalyptic number.

It is an amenable number.

19781632373 is a deficient number, since it is larger than the sum of its proper divisors (1).

19781632373 is an equidigital number, since it uses as much as digits as its factorization.

19781632373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1143072, while the sum is 50.

The spelling of 19781632373 in words is "nineteen billion, seven hundred eighty-one million, six hundred thirty-two thousand, three hundred seventy-three".