21516783746 has 32 divisors (see below), whose sum is σ = 32749774848. Its totient is φ = 10601772480.

The previous prime is 21516783733. The next prime is 21516783787. The reversal of 21516783746 is 64738761512.

It is a junction number, because it is equal to n+sod(n) for n = 21516783694 and 21516783703.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24932111 + ... + 24932973.

It is an arithmetic number, because the mean of its divisors is an integer number (1023430464).

Almost surely, 2^21516783746 is an apocalyptic number.

21516783746 is a deficient number, since it is larger than the sum of its proper divisors (11232991102).

21516783746 is a wasteful number, since it uses less digits than its factorization.

21516783746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1586.

The product of its digits is 1693440, while the sum is 50.

The spelling of 21516783746 in words is "twenty-one billion, five hundred sixteen million, seven hundred eighty-three thousand, seven hundred forty-six".