161621734753 has 2 divisors, whose sum is σ = 161621734754. Its totient is φ = 161621734752.

The previous prime is 161621734663. The next prime is 161621734777. The reversal of 161621734753 is 357437126161.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148758318864 + 12863415889 = 385692^2 + 113417^2 .

It is an emirp because it is prime and its reverse (357437126161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161621734753 - 2²¹ = 161619637601 is a prime.

It is a super-2 number, since 2×161621734753² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161621704753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80810867376 + 80810867377.

It is an arithmetic number, because the mean of its divisors is an integer number (80810867377).

Almost surely, 2^161621734753 is an apocalyptic number.

It is an amenable number.

161621734753 is a deficient number, since it is larger than the sum of its proper divisors (1).

161621734753 is an equidigital number, since it uses as much as digits as its factorization.

161621734753 is an evil number, because the sum of its binary digits is even.

The product of its digits is 635040, while the sum is 46.

The spelling of 161621734753 in words is "one hundred sixty-one billion, six hundred twenty-one million, seven hundred thirty-four thousand, seven hundred fifty-three".