161645776 has 10 divisors (see below), whose sum is σ = 313188722. Its totient is φ = 80822880.

The previous prime is 161645773. The next prime is 161645777. The reversal of 161645776 is 677546161.

It can be written as a sum of positive squares in only one way, i.e., 154355776 + 7290000 = 12424^2 + 2700^2 .

It is a super-2 number, since 2×161645776² = 52258713797284352, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161645773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5051415 + ... + 5051446.

Almost surely, 2^161645776 is an apocalyptic number.

161645776 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

161645776 is a deficient number, since it is larger than the sum of its proper divisors (151542946).

161645776 is a wasteful number, since it uses less digits than its factorization.

161645776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10102869 (or 10102863 counting only the distinct ones).

The product of its digits is 211680, while the sum is 43.

The square root of 161645776 is about 12713.9992134654. Note that the first 3 decimals coincide. The cubic root of 161645776 is about 544.7385621480.

The spelling of 161645776 in words is "one hundred sixty-one million, six hundred forty-five thousand, seven hundred seventy-six".