161669777 has 4 divisors (see below), whose sum is σ = 161696256. Its totient is φ = 161643300.

The previous prime is 161669771. The next prime is 161669797. The reversal of 161669777 is 777966161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 161669777 - 2¹⁸ = 161407633 is a prime.

It is a super-2 number, since 2×161669777² = 52274233590459458, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161669771) 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, 1088 + ... + 18014.

It is an arithmetic number, because the mean of its divisors is an integer number (40424064).

Almost surely, 2^161669777 is an apocalyptic number.

It is an amenable number.

161669777 is a deficient number, since it is larger than the sum of its proper divisors (26479).

161669777 is an equidigital number, since it uses as much as digits as its factorization.

161669777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26478.

The product of its digits is 666792, while the sum is 50.

The square root of 161669777 is about 12714.9430592512. The cubic root of 161669777 is about 544.7655215558.

The spelling of 161669777 in words is "one hundred sixty-one million, six hundred sixty-nine thousand, seven hundred seventy-seven".