1681952209 has 8 divisors (see below), whose sum is σ = 1922486720. Its totient is φ = 1441481616.

The previous prime is 1681952203. The next prime is 1681952221. The reversal of 1681952209 is 9022591861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1681952209 - 2³ = 1681952201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1681952201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74842 + ... + 94684.

It is an arithmetic number, because the mean of its divisors is an integer number (240310840).

Almost surely, 2^1681952209 is an apocalyptic number.

It is an amenable number.

1681952209 is a deficient number, since it is larger than the sum of its proper divisors (240534511).

1681952209 is a wasteful number, since it uses less digits than its factorization.

1681952209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31959.

The product of its (nonzero) digits is 77760, while the sum is 43.

The square root of 1681952209 is about 41011.6106608848. The cubic root of 1681952209 is about 1189.2446796871.

The spelling of 1681952209 in words is "one billion, six hundred eighty-one million, nine hundred fifty-two thousand, two hundred nine".