1625989 has 2 divisors, whose sum is σ = 1625990. Its totient is φ = 1625988.

The previous prime is 1625977. The next prime is 1625993. The reversal of 1625989 is 9895261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1085764 + 540225 = 1042^2 + 735^2 .

It is a cyclic number.

It is not a de Polignac number, because 1625989 - 2⁷ = 1625861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1625909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 812994 + 812995.

It is an arithmetic number, because the mean of its divisors is an integer number (812995).

2^1625989 is an apocalyptic number.

It is an amenable number.

1625989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1625989 is an equidigital number, since it uses as much as digits as its factorization.

1625989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 40.

The square root of 1625989 is about 1275.1427371083. The cubic root of 1625989 is about 117.5905805234.

The spelling of 1625989 in words is "one million, six hundred twenty-five thousand, nine hundred eighty-nine".