21517783930 has 32 divisors (see below), whose sum is σ = 39576854016. Its totient is φ = 8419563264.

The previous prime is 21517783927. The next prime is 21517783943. The reversal of 21517783930 is 3938771512.

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 15 ways as a sum of consecutive naturals, for example, 969922 + ... + 991858.

It is an arithmetic number, because the mean of its divisors is an integer number (1236776688).

Almost surely, 2^21517783930 is an apocalyptic number.

21517783930 is a deficient number, since it is larger than the sum of its proper divisors (18059070086).

21517783930 is a wasteful number, since it uses less digits than its factorization.

21517783930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24078.

The product of its (nonzero) digits is 317520, while the sum is 46.

The spelling of 21517783930 in words is "twenty-one billion, five hundred seventeen million, seven hundred eighty-three thousand, nine hundred thirty".