81930452287 has 2 divisors, whose sum is σ = 81930452288. Its totient is φ = 81930452286.

The previous prime is 81930452249. The next prime is 81930452333. The reversal of 81930452287 is 78225403918.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81930452287 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81930452287.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81930455287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40965226143 + 40965226144.

It is an arithmetic number, because the mean of its divisors is an integer number (40965226144).

Almost surely, 2^81930452287 is an apocalyptic number.

81930452287 is a deficient number, since it is larger than the sum of its proper divisors (1).

81930452287 is an equidigital number, since it uses as much as digits as its factorization.

81930452287 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 967680, while the sum is 49.

The spelling of 81930452287 in words is "eighty-one billion, nine hundred thirty million, four hundred fifty-two thousand, two hundred eighty-seven".