1948778644 has 6 divisors (see below), whose sum is σ = 3410362634. Its totient is φ = 974389320.

The previous prime is 1948778639. The next prime is 1948778647. The reversal of 1948778644 is 4468778491.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1252452100 + 696326544 = 35390^2 + 26388^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1948778647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 243597327 + ... + 243597334.

Almost surely, 2^1948778644 is an apocalyptic number.

It is an amenable number.

1948778644 is a deficient number, since it is larger than the sum of its proper divisors (1461583990).

1948778644 is a wasteful number, since it uses less digits than its factorization.

1948778644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 487194665 (or 487194663 counting only the distinct ones).

The product of its digits is 10838016, while the sum is 58.

The square root of 1948778644 is about 44144.9730320452. The cubic root of 1948778644 is about 1249.0720887417.

The spelling of 1948778644 in words is "one billion, nine hundred forty-eight million, seven hundred seventy-eight thousand, six hundred forty-four".