181381210537 has 2 divisors, whose sum is σ = 181381210538. Its totient is φ = 181381210536.

The previous prime is 181381210463. The next prime is 181381210553. The reversal of 181381210537 is 735012183181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 177973453161 + 3407757376 = 421869^2 + 58376^2 .

It is an emirp because it is prime and its reverse (735012183181) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-181381210537 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 181381210537.

It is not a weakly prime, because it can be changed into another prime (181381210567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90690605268 + 90690605269.

It is an arithmetic number, because the mean of its divisors is an integer number (90690605269).

Almost surely, 2^181381210537 is an apocalyptic number.

It is an amenable number.

181381210537 is a deficient number, since it is larger than the sum of its proper divisors (1).

181381210537 is an equidigital number, since it uses as much as digits as its factorization.

181381210537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 40.

The spelling of 181381210537 in words is "one hundred eighty-one billion, three hundred eighty-one million, two hundred ten thousand, five hundred thirty-seven".