21663003747 has 32 divisors (see below), whose sum is σ = 36031173120. Its totient is φ = 11247275520.

The previous prime is 21663003727. The next prime is 21663003757. The reversal of 21663003747 is 74730036612.

It is not a de Polignac number, because 21663003747 - 2⁷ = 21663003619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21663003727) 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 31 ways as a sum of consecutive naturals, for example, 407629 + ... + 457697.

It is an arithmetic number, because the mean of its divisors is an integer number (1125974160).

Almost surely, 2^21663003747 is an apocalyptic number.

21663003747 is a deficient number, since it is larger than the sum of its proper divisors (14368169373).

21663003747 is a wasteful number, since it uses less digits than its factorization.

21663003747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51963.

The product of its (nonzero) digits is 127008, while the sum is 39.

The spelling of 21663003747 in words is "twenty-one billion, six hundred sixty-three million, three thousand, seven hundred forty-seven".