81518963 has 2 divisors, whose sum is σ = 81518964. Its totient is φ = 81518962.

The previous prime is 81518951. The next prime is 81518977. The reversal of 81518963 is 36981518.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81518963 - 2¹⁴ = 81502579 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81518963.

It is not a weakly prime, because it can be changed into another prime (81518993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40759481 + 40759482.

It is an arithmetic number, because the mean of its divisors is an integer number (40759482).

Almost surely, 2^81518963 is an apocalyptic number.

81518963 is a deficient number, since it is larger than the sum of its proper divisors (1).

81518963 is an equidigital number, since it uses as much as digits as its factorization.

81518963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 41.

The square root of 81518963 is about 9028.7852449817. The cubic root of 81518963 is about 433.5969468332.

The spelling of 81518963 in words is "eighty-one million, five hundred eighteen thousand, nine hundred sixty-three".