1681227845 has 18 divisors (see below), whose sum is σ = 2218884486. Its totient is φ = 1221977680.

The previous prime is 1681227829. The next prime is 1681227857. The reversal of 1681227845 is 5487221861.

It can be written as a sum of positive squares in only one way, i.e., 1344982276 + 336245569 = 36674^2 + 18337^2 .

It is not a de Polignac number, because 1681227845 - 2⁴ = 1681227829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1681227796 and 1681227805.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1007702 + ... + 1009368.

Almost surely, 2^1681227845 is an apocalyptic number.

It is an amenable number.

1681227845 is a deficient number, since it is larger than the sum of its proper divisors (537656641).

1681227845 is an frugal number, since it uses more digits than its factorization.

1681227845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3361 (or 1683 counting only the distinct ones).

The product of its digits is 215040, while the sum is 44.

The square root of 1681227845 is about 41002.7785034136. The cubic root of 1681227845 is about 1189.0739317264.

The spelling of 1681227845 in words is "one billion, six hundred eighty-one million, two hundred twenty-seven thousand, eight hundred forty-five".