1663948913 has 4 divisors (see below), whose sum is σ = 1815217008. Its totient is φ = 1512680820.

The previous prime is 1663948889. The next prime is 1663948931. The reversal of 1663948913 is 3198493661.

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 a cyclic number.

It is not a de Polignac number, because 1663948913 - 2²⁴ = 1647171697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1663948973) 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, 75634031 + ... + 75634052.

It is an arithmetic number, because the mean of its divisors is an integer number (453804252).

Almost surely, 2^1663948913 is an apocalyptic number.

It is an amenable number.

1663948913 is a deficient number, since it is larger than the sum of its proper divisors (151268095).

1663948913 is a wasteful number, since it uses less digits than its factorization.

1663948913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151268094.

The product of its digits is 839808, while the sum is 50.

The square root of 1663948913 is about 40791.5299173738. The cubic root of 1663948913 is about 1184.9863002327.

The spelling of 1663948913 in words is "one billion, six hundred sixty-three million, nine hundred forty-eight thousand, nine hundred thirteen".