1663973 has 2 divisors, whose sum is σ = 1663974. Its totient is φ = 1663972.

The previous prime is 1663967. The next prime is 1663997. The reversal of 1663973 is 3793661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1643524 + 20449 = 1282^2 + 143^2 .

It is a cyclic number.

It is not a de Polignac number, because 1663973 - 2¹² = 1659877 is a prime.

It is a super-2 number, since 2×1663973² = 5537612289458, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1663913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831986 + 831987.

It is an arithmetic number, because the mean of its divisors is an integer number (831987).

2^1663973 is an apocalyptic number.

It is an amenable number.

1663973 is a deficient number, since it is larger than the sum of its proper divisors (1).

1663973 is an equidigital number, since it uses as much as digits as its factorization.

1663973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20412, while the sum is 35.

The square root of 1663973 is about 1289.9507742546. The cubic root of 1663973 is about 118.4992018082.

The spelling of 1663973 in words is "one million, six hundred sixty-three thousand, nine hundred seventy-three".