21244237738 has 16 divisors (see below), whose sum is σ = 33106699080. Its totient is φ = 10211815936.

The previous prime is 21244237711. The next prime is 21244237739. The reversal of 21244237738 is 83773244212.

It can be written as a sum of positive squares in 4 ways, for example, as 10545852249 + 10698385489 = 102693^2 + 103433^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21244237694 and 21244237703.

It is not an unprimeable number, because it can be changed into a prime (21244237739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 772495 + ... + 799522.

Almost surely, 2^21244237738 is an apocalyptic number.

21244237738 is a deficient number, since it is larger than the sum of its proper divisors (11862461342).

21244237738 is a wasteful number, since it uses less digits than its factorization.

21244237738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1572281.

The product of its digits is 451584, while the sum is 43.

The spelling of 21244237738 in words is "twenty-one billion, two hundred forty-four million, two hundred thirty-seven thousand, seven hundred thirty-eight".