21238630756 has 18 divisors (see below), whose sum is σ = 43235784438. Its totient is φ = 9102270240.

The previous prime is 21238630753. The next prime is 21238630759. The reversal of 21238630756 is 65703683212.

It is an interprime number because it is at equal distance from previous prime (21238630753) and next prime (21238630759).

It can be written as a sum of positive squares in only one way, i.e., 20572164900 + 666465856 = 143430^2 + 25816^2 .

It is not an unprimeable number, because it can be changed into a prime (21238630753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 54179985 + ... + 54180376.

Almost surely, 2^21238630756 is an apocalyptic number.

It is an amenable number.

21238630756 is an abundant number, since it is smaller than the sum of its proper divisors (21997153682).

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

21238630756 is a wasteful number, since it uses less digits than its factorization.

21238630756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108360379 (or 108360370 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 43.

The spelling of 21238630756 in words is "twenty-one billion, two hundred thirty-eight million, six hundred thirty thousand, seven hundred fifty-six".