161687141477 has 4 divisors (see below), whose sum is σ = 163902033900. Its totient is φ = 159472249056.

The previous prime is 161687141453. The next prime is 161687141479. The reversal of 161687141477 is 774141786161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 774141786161 = 114493 ⋅6761477.

It can be written as a sum of positive squares in 2 ways, for example, as 88156141921 + 73530999556 = 296911^2 + 271166^2 .

It is a cyclic number.

It is not a de Polignac number, because 161687141477 - 2⁸ = 161687141221 is a prime.

It is a super-2 number, since 2×161687141477² (a number of 23 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 (161687141479) 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, 1107446102 + ... + 1107446247.

It is an arithmetic number, because the mean of its divisors is an integer number (40975508475).

Almost surely, 2^161687141477 is an apocalyptic number.

It is an amenable number.

161687141477 is a deficient number, since it is larger than the sum of its proper divisors (2214892423).

161687141477 is an equidigital number, since it uses as much as digits as its factorization.

161687141477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2214892422.

The product of its digits is 1580544, while the sum is 53.

The spelling of 161687141477 in words is "one hundred sixty-one billion, six hundred eighty-seven million, one hundred forty-one thousand, four hundred seventy-seven".