1663949 has 4 divisors (see below), whose sum is σ = 1901664. Its totient is φ = 1426236.

The previous prime is 1663919. The next prime is 1663951. The reversal of 1663949 is 9493661.

1663949 = T₆₈₆ + T₆₈₇ + ... + T₆₉₂.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1663949 - 2⁸ = 1663693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118847 + ... + 118860.

It is an arithmetic number, because the mean of its divisors is an integer number (475416).

2^1663949 is an apocalyptic number.

It is an amenable number.

1663949 is a deficient number, since it is larger than the sum of its proper divisors (237715).

1663949 is an equidigital number, since it uses as much as digits as its factorization.

1663949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237714.

The product of its digits is 34992, while the sum is 38.

The square root of 1663949 is about 1289.9414715405. The cubic root of 1663949 is about 118.4986320885.

The spelling of 1663949 in words is "one million, six hundred sixty-three thousand, nine hundred forty-nine".