181420774731 has 40 divisors (see below), whose sum is σ = 309776630240. Its totient is φ = 103652462592.

The previous prime is 181420774723. The next prime is 181420774741. The reversal of 181420774731 is 137477024181.

181420774731 is a `hidden beast` number, since 181 + 420 + 7 + 7 + 47 + 3 + 1 = 666.

181420774731 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 181420774731 - 2³ = 181420774723 is a prime.

It is a super-2 number, since 2×181420774731² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (181420774741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4122315 + ... + 4166091.

It is an arithmetic number, because the mean of its divisors is an integer number (7744415756).

Almost surely, 2^181420774731 is an apocalyptic number.

181420774731 is a deficient number, since it is larger than the sum of its proper divisors (128355855509).

181420774731 is an equidigital number, since it uses as much as digits as its factorization.

181420774731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51105 (or 51096 counting only the distinct ones).

The product of its (nonzero) digits is 263424, while the sum is 45.

The spelling of 181420774731 in words is "one hundred eighty-one billion, four hundred twenty million, seven hundred seventy-four thousand, seven hundred thirty-one".