1663543694 has 4 divisors (see below), whose sum is σ = 2495315544. Its totient is φ = 831771846.

The previous prime is 1663543691. The next prime is 1663543699. The reversal of 1663543694 is 4963453661.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663543691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 415885922 + ... + 415885925.

It is an arithmetic number, because the mean of its divisors is an integer number (623828886).

Almost surely, 2^1663543694 is an apocalyptic number.

1663543694 is a deficient number, since it is larger than the sum of its proper divisors (831771850).

1663543694 is an equidigital number, since it uses as much as digits as its factorization.

1663543694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 831771849.

The product of its digits is 1399680, while the sum is 47.

The square root of 1663543694 is about 40786.5626646816. The cubic root of 1663543694 is about 1184.8900997736.

The spelling of 1663543694 in words is "one billion, six hundred sixty-three million, five hundred forty-three thousand, six hundred ninety-four".