1681668151 has 4 divisors (see below), whose sum is σ = 1682966032. Its totient is φ = 1680370272.

The previous prime is 1681668139. The next prime is 1681668173. The reversal of 1681668151 is 1518661861.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1681668151 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1681668098 and 1681668107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681668451) 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, 646995 + ... + 649588.

It is an arithmetic number, because the mean of its divisors is an integer number (420741508).

Almost surely, 2^1681668151 is an apocalyptic number.

1681668151 is a deficient number, since it is larger than the sum of its proper divisors (1297881).

1681668151 is a wasteful number, since it uses less digits than its factorization.

1681668151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1297880.

The product of its digits is 69120, while the sum is 43.

The square root of 1681668151 is about 41008.1473734184. The cubic root of 1681668151 is about 1189.1777270348.

The spelling of 1681668151 in words is "one billion, six hundred eighty-one million, six hundred sixty-eight thousand, one hundred fifty-one".