81503623987 has 2 divisors, whose sum is σ = 81503623988. Its totient is φ = 81503623986.

The previous prime is 81503623937. The next prime is 81503624009. The reversal of 81503623987 is 78932630518.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81503623987 - 2²⁷ = 81369406259 is a prime.

It is not a weakly prime, because it can be changed into another prime (81503623937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40751811993 + 40751811994.

It is an arithmetic number, because the mean of its divisors is an integer number (40751811994).

Almost surely, 2^81503623987 is an apocalyptic number.

81503623987 is a deficient number, since it is larger than the sum of its proper divisors (1).

81503623987 is an equidigital number, since it uses as much as digits as its factorization.

81503623987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2177280, while the sum is 52.

The spelling of 81503623987 in words is "eighty-one billion, five hundred three million, six hundred twenty-three thousand, nine hundred eighty-seven".