161451179521 has 2 divisors, whose sum is σ = 161451179522. Its totient is φ = 161451179520.

The previous prime is 161451179507. The next prime is 161451179581. The reversal of 161451179521 is 125971154161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138759975025 + 22691204496 = 372505^2 + 150636^2 .

It is a cyclic number.

It is not a de Polignac number, because 161451179521 - 2²¹ = 161449082369 is a prime.

It is not a weakly prime, because it can be changed into another prime (161451179581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80725589760 + 80725589761.

It is an arithmetic number, because the mean of its divisors is an integer number (80725589761).

Almost surely, 2^161451179521 is an apocalyptic number.

It is an amenable number.

161451179521 is a deficient number, since it is larger than the sum of its proper divisors (1).

161451179521 is an equidigital number, since it uses as much as digits as its factorization.

161451179521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75600, while the sum is 43.

The spelling of 161451179521 in words is "one hundred sixty-one billion, four hundred fifty-one million, one hundred seventy-nine thousand, five hundred twenty-one".