1620667 has 2 divisors, whose sum is σ = 1620668. Its totient is φ = 1620666.

The previous prime is 1620631. The next prime is 1620677. The reversal of 1620667 is 7660261.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1620667 - 2⁷ = 1620539 is a prime.

It is not a weakly prime, because it can be changed into another prime (1620617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810333 + 810334.

It is an arithmetic number, because the mean of its divisors is an integer number (810334).

2^1620667 is an apocalyptic number.

1620667 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620667 is an equidigital number, since it uses as much as digits as its factorization.

1620667 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 1620667 is about 1273.0542015170. The cubic root of 1620667 is about 117.4621456451.

The spelling of 1620667 in words is "one million, six hundred twenty thousand, six hundred sixty-seven".