1620121 has 2 divisors, whose sum is σ = 1620122. Its totient is φ = 1620120.

The previous prime is 1620107. The next prime is 1620133. The reversal of 1620121 is 1210261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1354896 + 265225 = 1164^2 + 515^2 .

It is a cyclic number.

It is not a de Polignac number, because 1620121 - 2¹⁹ = 1095833 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1620161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810060 + 810061.

It is an arithmetic number, because the mean of its divisors is an integer number (810061).

2^1620121 is an apocalyptic number.

It is an amenable number.

1620121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620121 is an equidigital number, since it uses as much as digits as its factorization.

1620121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1620121 is about 1272.8397385374. The cubic root of 1620121 is about 117.4489532301.

Adding to 1620121 its reverse (1210261), we get a palindrome (2830382).

The spelling of 1620121 in words is "one million, six hundred twenty thousand, one hundred twenty-one".