21780384530 has 32 divisors (see below), whose sum is σ = 42036330240. Its totient is φ = 8095875840.

The previous prime is 21780384529. The next prime is 21780384617. The reversal of 21780384530 is 3548308712.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 797456 + ... + 824315.

It is an arithmetic number, because the mean of its divisors is an integer number (1313635320).

Almost surely, 2^21780384530 is an apocalyptic number.

21780384530 is a deficient number, since it is larger than the sum of its proper divisors (20255945710).

21780384530 is a wasteful number, since it uses less digits than its factorization.

21780384530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1621874.

The product of its (nonzero) digits is 161280, while the sum is 41.

The spelling of 21780384530 in words is "twenty-one billion, seven hundred eighty million, three hundred eighty-four thousand, five hundred thirty".