1994668651 has 2 divisors, whose sum is σ = 1994668652. Its totient is φ = 1994668650.

The previous prime is 1994668639. The next prime is 1994668693. The reversal of 1994668651 is 1568664991.

It is a weak prime.

It is an emirp because it is prime and its reverse (1568664991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1994668651 - 2⁷ = 1994668523 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1994668592 and 1994668601.

It is not a weakly prime, because it can be changed into another prime (1994668751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 997334325 + 997334326.

It is an arithmetic number, because the mean of its divisors is an integer number (997334326).

Almost surely, 2^1994668651 is an apocalyptic number.

1994668651 is a deficient number, since it is larger than the sum of its proper divisors (1).

1994668651 is an equidigital number, since it uses as much as digits as its factorization.

1994668651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2799360, while the sum is 55.

The square root of 1994668651 is about 44661.7134803402. The cubic root of 1994668651 is about 1258.8005405283.

The spelling of 1994668651 in words is "one billion, nine hundred ninety-four million, six hundred sixty-eight thousand, six hundred fifty-one".