81900331293 has 8 divisors (see below), whose sum is σ = 119127754656. Its totient is φ = 49636564400.

The previous prime is 81900331273. The next prime is 81900331313. The reversal of 81900331293 is 39213300918.

It is an interprime number because it is at equal distance from previous prime (81900331273) and next prime (81900331313).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81900331293 - 2²¹ = 81898234141 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81900331223) 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 in 7 ways as a sum of consecutive naturals, for example, 1240914078 + ... + 1240914143.

It is an arithmetic number, because the mean of its divisors is an integer number (14890969332).

Almost surely, 2^81900331293 is an apocalyptic number.

It is an amenable number.

81900331293 is a deficient number, since it is larger than the sum of its proper divisors (37227423363).

81900331293 is a wasteful number, since it uses less digits than its factorization.

81900331293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2481828235.

The product of its (nonzero) digits is 34992, while the sum is 39.

The spelling of 81900331293 in words is "eighty-one billion, nine hundred million, three hundred thirty-one thousand, two hundred ninety-three".