646378151 has 2 divisors, whose sum is σ = 646378152. Its totient is φ = 646378150.

The previous prime is 646378133. The next prime is 646378181. The reversal of 646378151 is 151873646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646378151 - 2⁶ = 646378087 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 646378099 and 646378108.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646378111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323189075 + 323189076.

It is an arithmetic number, because the mean of its divisors is an integer number (323189076).

Almost surely, 2^646378151 is an apocalyptic number.

646378151 is a deficient number, since it is larger than the sum of its proper divisors (1).

646378151 is an equidigital number, since it uses as much as digits as its factorization.

646378151 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 41.

The square root of 646378151 is about 25423.9680419875. The cubic root of 646378151 is about 864.6271911890.

The spelling of 646378151 in words is "six hundred forty-six million, three hundred seventy-eight thousand, one hundred fifty-one".