1908661 has 2 divisors, whose sum is σ = 1908662. Its totient is φ = 1908660.

The previous prime is 1908659. The next prime is 1908667. The reversal of 1908661 is 1668091.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1425636 + 483025 = 1194^2 + 695^2 .

It is a cyclic number.

It is not a de Polignac number, because 1908661 - 2¹ = 1908659 is a prime.

Together with 1908659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1908667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 954330 + 954331.

It is an arithmetic number, because the mean of its divisors is an integer number (954331).

2^1908661 is an apocalyptic number.

It is an amenable number.

1908661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1908661 is an equidigital number, since it uses as much as digits as its factorization.

1908661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 1908661 is about 1381.5429779779. The cubic root of 1908661 is about 124.0441440123.

The spelling of 1908661 in words is "one million, nine hundred eight thousand, six hundred sixty-one".