1667651 has 2 divisors, whose sum is σ = 1667652. Its totient is φ = 1667650.

The previous prime is 1667647. The next prime is 1667663. The reversal of 1667651 is 1567661.

It is a weak prime.

It is an emirp because it is prime and its reverse (1567661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1667651 - 2² = 1667647 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1667641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833825 + 833826.

It is an arithmetic number, because the mean of its divisors is an integer number (833826).

2^1667651 is an apocalyptic number.

1667651 is a deficient number, since it is larger than the sum of its proper divisors (1).

1667651 is an equidigital number, since it uses as much as digits as its factorization.

1667651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 32.

The square root of 1667651 is about 1291.3756231244. The cubic root of 1667651 is about 118.5864466804.

The spelling of 1667651 in words is "one million, six hundred sixty-seven thousand, six hundred fifty-one".