21782740434 has 64 divisors (see below), whose sum is σ = 53640437760. Its totient is φ = 5742607680.

The previous prime is 21782740423. The next prime is 21782740453. The reversal of 21782740434 is 43404728712.

It is a Harshad number since it is a multiple of its sum of digits (42).

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 31 ways as a sum of consecutive naturals, for example, 1696579 + ... + 1709369.

It is an arithmetic number, because the mean of its divisors is an integer number (838131840).

Almost surely, 2^21782740434 is an apocalyptic number.

21782740434 is an abundant number, since it is smaller than the sum of its proper divisors (31857697326).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21782740434 is a wasteful number, since it uses less digits than its factorization.

21782740434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15935.

The product of its (nonzero) digits is 301056, while the sum is 42.

The spelling of 21782740434 in words is "twenty-one billion, seven hundred eighty-two million, seven hundred forty thousand, four hundred thirty-four".