21768652426 has 4 divisors (see below), whose sum is σ = 32652978642. Its totient is φ = 10884326212.

The previous prime is 21768652403. The next prime is 21768652441. The reversal of 21768652426 is 62425686712.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20259252225 + 1509400201 = 142335^2 + 38851^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21768652426.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5442163105 + ... + 5442163108.

Almost surely, 2^21768652426 is an apocalyptic number.

21768652426 is a deficient number, since it is larger than the sum of its proper divisors (10884326216).

21768652426 is a wasteful number, since it uses less digits than its factorization.

21768652426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10884326215.

The product of its digits is 1935360, while the sum is 49.

The spelling of 21768652426 in words is "twenty-one billion, seven hundred sixty-eight million, six hundred fifty-two thousand, four hundred twenty-six".