1619861 has 2 divisors, whose sum is σ = 1619862. Its totient is φ = 1619860.

The previous prime is 1619857. The next prime is 1619887. The reversal of 1619861 is 1689161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 970225 + 649636 = 985^2 + 806^2 .

It is a cyclic number.

It is not a de Polignac number, because 1619861 - 2² = 1619857 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1619831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 809930 + 809931.

It is an arithmetic number, because the mean of its divisors is an integer number (809931).

2^1619861 is an apocalyptic number.

It is an amenable number.

1619861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1619861 is an equidigital number, since it uses as much as digits as its factorization.

1619861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 32.

The square root of 1619861 is about 1272.7376006074. The cubic root of 1619861 is about 117.4426700859.

The spelling of 1619861 in words is "one million, six hundred nineteen thousand, eight hundred sixty-one".