21283783718381 has 2 divisors, whose sum is σ = 21283783718382. Its totient is φ = 21283783718380.

The previous prime is 21283783718359. The next prime is 21283783718411. The reversal of 21283783718381 is 18381738738212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13458846076900 + 7824937641481 = 3668630^2 + 2797309^2 .

It is a cyclic number.

It is not a de Polignac number, because 21283783718381 - 2³⁸ = 21008905811437 is a prime.

It is a super-2 number, since 2×21283783718381² (a number of 27 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21283783718081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10641891859190 + 10641891859191.

It is an arithmetic number, because the mean of its divisors is an integer number (10641891859191).

Almost surely, 2^{21283783718381} is an apocalyptic number.

It is an amenable number.

21283783718381 is a deficient number, since it is larger than the sum of its proper divisors (1).

21283783718381 is an equidigital number, since it uses as much as digits as its factorization.

21283783718381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21676032, while the sum is 62.

The spelling of 21283783718381 in words is "twenty-one trillion, two hundred eighty-three billion, seven hundred eighty-three million, seven hundred eighteen thousand, three hundred eighty-one".