161642344451477 has 4 divisors (see below), whose sum is σ = 161642408303820. Its totient is φ = 161642280599136.

The previous prime is 161642344451447. The next prime is 161642344451491. The reversal of 161642344451477 is 774154443246161.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 124831258729681 + 36811085721796 = 11172791^2 + 6067214^2 .

It is a cyclic number.

It is not a de Polignac number, because 161642344451477 - 2²⁰ = 161642343402901 is a prime.

It is a super-2 number, since 2×161642344451477² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161642344451417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27965102 + ... + 33246527.

It is an arithmetic number, because the mean of its divisors is an integer number (40410602075955).

Almost surely, 2^{161642344451477} is an apocalyptic number.

It is an amenable number.

161642344451477 is a deficient number, since it is larger than the sum of its proper divisors (63852343).

161642344451477 is an equidigital number, since it uses as much as digits as its factorization.

161642344451477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63852342.

The product of its digits is 54190080, while the sum is 59.

The spelling of 161642344451477 in words is "one hundred sixty-one trillion, six hundred forty-two billion, three hundred forty-four million, four hundred fifty-one thousand, four hundred seventy-seven".