21044687746 has 8 divisors (see below), whose sum is σ = 31605390144. Its totient is φ = 10509557700.

The previous prime is 21044687737. The next prime is 21044687761. The reversal of 21044687746 is 64778644012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21044687746.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 6391030 + ... + 6394321.

It is an arithmetic number, because the mean of its divisors is an integer number (3950673768).

Almost surely, 2^21044687746 is an apocalyptic number.

21044687746 is a deficient number, since it is larger than the sum of its proper divisors (10560702398).

21044687746 is a wasteful number, since it uses less digits than its factorization.

21044687746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12786176.

The product of its (nonzero) digits is 1806336, while the sum is 49.

The spelling of 21044687746 in words is "twenty-one billion, forty-four million, six hundred eighty-seven thousand, seven hundred forty-six".