84519731381 has 2 divisors, whose sum is σ = 84519731382. Its totient is φ = 84519731380.

The previous prime is 84519731377. The next prime is 84519731437. The reversal of 84519731381 is 18313791548.

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., 62485000900 + 22034730481 = 249970^2 + 148441^2 .

It is a cyclic number.

It is not a de Polignac number, because 84519731381 - 2² = 84519731377 is a prime.

It is a super-2 number, since 2×84519731381² (a number of 23 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 (84519731341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42259865690 + 42259865691.

It is an arithmetic number, because the mean of its divisors is an integer number (42259865691).

Almost surely, 2^84519731381 is an apocalyptic number.

It is an amenable number.

84519731381 is a deficient number, since it is larger than the sum of its proper divisors (1).

84519731381 is an equidigital number, since it uses as much as digits as its factorization.

84519731381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 725760, while the sum is 50.

The spelling of 84519731381 in words is "eighty-four billion, five hundred nineteen million, seven hundred thirty-one thousand, three hundred eighty-one".