180156361921 has 2 divisors, whose sum is σ = 180156361922. Its totient is φ = 180156361920.

The previous prime is 180156361873. The next prime is 180156361939. The reversal of 180156361921 is 129163651081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110928963600 + 69227398321 = 333060^2 + 263111^2 .

It is a cyclic number.

It is not a de Polignac number, because 180156361921 - 2²¹ = 180154264769 is a prime.

It is a super-2 number, since 2×180156361921² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (180156361951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90078180960 + 90078180961.

It is an arithmetic number, because the mean of its divisors is an integer number (90078180961).

Almost surely, 2^180156361921 is an apocalyptic number.

It is an amenable number.

180156361921 is a deficient number, since it is larger than the sum of its proper divisors (1).

180156361921 is an equidigital number, since it uses as much as digits as its factorization.

180156361921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 43.

The spelling of 180156361921 in words is "one hundred eighty billion, one hundred fifty-six million, three hundred sixty-one thousand, nine hundred twenty-one".