81900313357 has 2 divisors, whose sum is σ = 81900313358. Its totient is φ = 81900313356.

The previous prime is 81900313309. The next prime is 81900313361. The reversal of 81900313357 is 75331300918.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50310938601 + 31589374756 = 224301^2 + 177734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81900313357 is a prime.

It is a super-2 number, since 2×81900313357² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81900313367) 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, 40950156678 + 40950156679.

It is an arithmetic number, because the mean of its divisors is an integer number (40950156679).

Almost surely, 2^81900313357 is an apocalyptic number.

It is an amenable number.

81900313357 is a deficient number, since it is larger than the sum of its proper divisors (1).

81900313357 is an equidigital number, since it uses as much as digits as its factorization.

81900313357 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 68040, while the sum is 40.

The spelling of 81900313357 in words is "eighty-one billion, nine hundred million, three hundred thirteen thousand, three hundred fifty-seven".