1620769 has 2 divisors, whose sum is σ = 1620770. Its totient is φ = 1620768.

The previous prime is 1620743. The next prime is 1620803. The reversal of 1620769 is 9670261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1595169 + 25600 = 1263^2 + 160^2 .

It is a cyclic number.

It is not a de Polignac number, because 1620769 - 2⁹ = 1620257 is a prime.

It is a super-2 number, since 2×1620769² = 5253784302722, which contains 22 as substring.

It is an Ulam number.

1620769 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1620769.

It is not a weakly prime, because it can be changed into another prime (1620739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810384 + 810385.

It is an arithmetic number, because the mean of its divisors is an integer number (810385).

2^1620769 is an apocalyptic number.

It is an amenable number.

1620769 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620769 is an equidigital number, since it uses as much as digits as its factorization.

1620769 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 1620769 is about 1273.0942620246. The cubic root of 1620769 is about 117.4646098337.

The spelling of 1620769 in words is "one million, six hundred twenty thousand, seven hundred sixty-nine".