1628621 has 2 divisors, whose sum is σ = 1628622. Its totient is φ = 1628620.

The previous prime is 1628603. The next prime is 1628633. The reversal of 1628621 is 1268261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1416100 + 212521 = 1190^2 + 461^2 .

It is an emirp because it is prime and its reverse (1268261) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1628621 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1621621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 814310 + 814311.

It is an arithmetic number, because the mean of its divisors is an integer number (814311).

2^1628621 is an apocalyptic number.

It is an amenable number.

1628621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1628621 is an equidigital number, since it uses as much as digits as its factorization.

1628621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 26.

The square root of 1628621 is about 1276.1743611278. The cubic root of 1628621 is about 117.6539945568.

The spelling of 1628621 in words is "one million, six hundred twenty-eight thousand, six hundred twenty-one".