1628381 has 2 divisors, whose sum is σ = 1628382. Its totient is φ = 1628380.

The previous prime is 1628369. The next prime is 1628383. The reversal of 1628381 is 1838261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1522756 + 105625 = 1234^2 + 325^2 .

It is a cyclic number.

It is not a de Polignac number, because 1628381 - 2⁶ = 1628317 is a prime.

It is a super-2 number, since 2×1628381² = 5303249362322, which contains 22 as substring.

Together with 1628383, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1628383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 814190 + 814191.

It is an arithmetic number, because the mean of its divisors is an integer number (814191).

2^1628381 is an apocalyptic number.

It is an amenable number.

1628381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1628381 is an equidigital number, since it uses as much as digits as its factorization.

1628381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 29.

The square root of 1628381 is about 1276.0803266252. The cubic root of 1628381 is about 117.6482149543.

The spelling of 1628381 in words is "one million, six hundred twenty-eight thousand, three hundred eighty-one".