646154401 has 2 divisors, whose sum is σ = 646154402. Its totient is φ = 646154400.

The previous prime is 646154389. The next prime is 646154441. The reversal of 646154401 is 104451646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 497290000 + 148864401 = 22300^2 + 12201^2 .

It is a cyclic number.

It is not a de Polignac number, because 646154401 - 2¹³ = 646146209 is a prime.

It is equal to p_33603880 and since 646154401 and 33603880 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (646154441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323077200 + 323077201.

It is an arithmetic number, because the mean of its divisors is an integer number (323077201).

Almost surely, 2^646154401 is an apocalyptic number.

It is an amenable number.

646154401 is a deficient number, since it is larger than the sum of its proper divisors (1).

646154401 is an equidigital number, since it uses as much as digits as its factorization.

646154401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 646154401 is about 25419.5672858528. The cubic root of 646154401 is about 864.5274133418.

The spelling of 646154401 in words is "six hundred forty-six million, one hundred fifty-four thousand, four hundred one".