646619 has 2 divisors, whose sum is σ = 646620. Its totient is φ = 646618.

The previous prime is 646609. The next prime is 646631. The reversal of 646619 is 916646.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646619 is a prime.

It is a super-2 number, since 2×646619² = 836232262322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (646609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323309 + 323310.

It is an arithmetic number, because the mean of its divisors is an integer number (323310).

2⁶⁴⁶⁶¹⁹ is an apocalyptic number.

646619 is a deficient number, since it is larger than the sum of its proper divisors (1).

646619 is an equidigital number, since it uses as much as digits as its factorization.

646619 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 32.

The square root of 646619 is about 804.1262338713. The cubic root of 646619 is about 86.4734568341.

The spelling of 646619 in words is "six hundred forty-six thousand, six hundred nineteen".