1663878388 has 6 divisors (see below), whose sum is σ = 2911787186. Its totient is φ = 831939192.

The previous prime is 1663878373. The next prime is 1663878389. The reversal of 1663878388 is 8838783661.

It can be written as a sum of positive squares in only one way, i.e., 917605264 + 746273124 = 30292^2 + 27318^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663878389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 207984795 + ... + 207984802.

Almost surely, 2^1663878388 is an apocalyptic number.

It is an amenable number.

1663878388 is a deficient number, since it is larger than the sum of its proper divisors (1247908798).

1663878388 is a wasteful number, since it uses less digits than its factorization.

1663878388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415969601 (or 415969599 counting only the distinct ones).

The product of its digits is 9289728, while the sum is 58.

The square root of 1663878388 is about 40790.6654517918. The cubic root of 1663878388 is about 1184.9695584648.

The spelling of 1663878388 in words is "one billion, six hundred sixty-three million, eight hundred seventy-eight thousand, three hundred eighty-eight".