81018974453783 has 2 divisors, whose sum is σ = 81018974453784. Its totient is φ = 81018974453782.

The previous prime is 81018974453759. The next prime is 81018974453803. The reversal of 81018974453783 is 38735447981018.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81018974453783 - 2¹² = 81018974449687 is a prime.

It is a super-2 number, since 2×81018974453783² (a number of 29 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81018974053783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40509487226891 + 40509487226892.

It is an arithmetic number, because the mean of its divisors is an integer number (40509487226892).

Almost surely, 2^{81018974453783} is an apocalyptic number.

81018974453783 is a deficient number, since it is larger than the sum of its proper divisors (1).

81018974453783 is an equidigital number, since it uses as much as digits as its factorization.

81018974453783 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162570240, while the sum is 68.

The spelling of 81018974453783 in words is "eighty-one trillion, eighteen billion, nine hundred seventy-four million, four hundred fifty-three thousand, seven hundred eighty-three".