20693380921 has 2 divisors, whose sum is σ = 20693380922. Its totient is φ = 20693380920.

The previous prime is 20693380919. The next prime is 20693380937. The reversal of 20693380921 is 12908339602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17811838521 + 2881542400 = 133461^2 + 53680^2 .

It is a cyclic number.

It is not a de Polignac number, because 20693380921 - 2¹ = 20693380919 is a prime.

Together with 20693380919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20693380021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10346690460 + 10346690461.

It is an arithmetic number, because the mean of its divisors is an integer number (10346690461).

Almost surely, 2^20693380921 is an apocalyptic number.

It is an amenable number.

20693380921 is a deficient number, since it is larger than the sum of its proper divisors (1).

20693380921 is an equidigital number, since it uses as much as digits as its factorization.

20693380921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 43.

The spelling of 20693380921 in words is "twenty billion, six hundred ninety-three million, three hundred eighty thousand, nine hundred twenty-one".