181381212553 has 2 divisors, whose sum is σ = 181381212554. Its totient is φ = 181381212552.

The previous prime is 181381212541. The next prime is 181381212587. The reversal of 181381212553 is 355212183181.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 144044539024 + 37336673529 = 379532^2 + 193227^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-181381212553 is a prime.

It is not a weakly prime, because it can be changed into another prime (181381212503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90690606276 + 90690606277.

It is an arithmetic number, because the mean of its divisors is an integer number (90690606277).

Almost surely, 2^181381212553 is an apocalyptic number.

It is an amenable number.

181381212553 is a deficient number, since it is larger than the sum of its proper divisors (1).

181381212553 is an equidigital number, since it uses as much as digits as its factorization.

181381212553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 57600, while the sum is 40.

The spelling of 181381212553 in words is "one hundred eighty-one billion, three hundred eighty-one million, two hundred twelve thousand, five hundred fifty-three".