21238379748 has 18 divisors (see below), whose sum is σ = 53685904454. Its totient is φ = 7079459904.

The previous prime is 21238379741. The next prime is 21238379749. The reversal of 21238379748 is 84797383212.

21238379748 is a `hidden beast` number, since 212 + 383 + 7 + 9 + 7 + 48 = 666.

It can be written as a sum of positive squares in only one way, i.e., 12463936164 + 8774443584 = 111642^2 + 93672^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a junction number, because it is equal to n+sod(n) for n = 21238379694 and 21238379703.

It is not an unprimeable number, because it can be changed into a prime (21238379741) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 294977461 + ... + 294977532.

Almost surely, 2^21238379748 is an apocalyptic number.

It is an amenable number.

21238379748 is an abundant number, since it is smaller than the sum of its proper divisors (32447524706).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21238379748 is a wasteful number, since it uses less digits than its factorization.

21238379748 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 589955003 (or 589954998 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 54.

The spelling of 21238379748 in words is "twenty-one billion, two hundred thirty-eight million, three hundred seventy-nine thousand, seven hundred forty-eight".