1620841 has 2 divisors, whose sum is σ = 1620842. Its totient is φ = 1620840.

The previous prime is 1620823. The next prime is 1620881. The reversal of 1620841 is 1480261.

1620841 = T₁₀₃₈ + T₁₀₃₉ + T₁₀₄₀.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1265625 + 355216 = 1125^2 + 596^2 .

It is an emirp because it is prime and its reverse (1480261) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1620841 - 2⁹ = 1620329 is a prime.

It is not a weakly prime, because it can be changed into another prime (1620811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810420 + 810421.

It is an arithmetic number, because the mean of its divisors is an integer number (810421).

2^1620841 is an apocalyptic number.

1620841 is the 1040-th centered triangular number.

It is an amenable number.

1620841 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620841 is an equidigital number, since it uses as much as digits as its factorization.

1620841 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 1620841 is about 1273.1225392711. The cubic root of 1620841 is about 117.4663491987.

The spelling of 1620841 in words is "one million, six hundred twenty thousand, eight hundred forty-one".