1961657 has 2 divisors, whose sum is σ = 1961658. Its totient is φ = 1961656.

The previous prime is 1961653. The next prime is 1961669. The reversal of 1961657 is 7561691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1771561 + 190096 = 1331^2 + 436^2 .

It is an emirp because it is prime and its reverse (7561691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1961657 - 2² = 1961653 is a prime.

It is not a weakly prime, because it can be changed into another prime (1961651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 980828 + 980829.

It is an arithmetic number, because the mean of its divisors is an integer number (980829).

2^1961657 is an apocalyptic number.

It is an amenable number.

1961657 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961657 is an equidigital number, since it uses as much as digits as its factorization.

1961657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11340, while the sum is 35.

The square root of 1961657 is about 1400.5916606920. The cubic root of 1961657 is about 125.1817516028.

The spelling of 1961657 in words is "one million, nine hundred sixty-one thousand, six hundred fifty-seven".