1668992251 has 2 divisors, whose sum is σ = 1668992252. Its totient is φ = 1668992250.

The previous prime is 1668992203. The next prime is 1668992261. The reversal of 1668992251 is 1522998661.

It is a strong prime.

It is an emirp because it is prime and its reverse (1522998661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1668992251 - 2⁹ = 1668991739 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1668992195 and 1668992204.

It is not a weakly prime, because it can be changed into another prime (1668992201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834496125 + 834496126.

It is an arithmetic number, because the mean of its divisors is an integer number (834496126).

Almost surely, 2^1668992251 is an apocalyptic number.

1668992251 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668992251 is an equidigital number, since it uses as much as digits as its factorization.

1668992251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 466560, while the sum is 49.

The square root of 1668992251 is about 40853.3015924050. The cubic root of 1668992251 is about 1186.1823022263.

The spelling of 1668992251 in words is "one billion, six hundred sixty-eight million, nine hundred ninety-two thousand, two hundred fifty-one".