21008282434 has 4 divisors (see below), whose sum is σ = 31512423654. Its totient is φ = 10504141216.

The previous prime is 21008282419. The next prime is 21008282521. The reversal of 21008282434 is 43428280012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16981999225 + 4026283209 = 130315^2 + 63453^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21008282434.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5252070607 + ... + 5252070610.

Almost surely, 2^21008282434 is an apocalyptic number.

21008282434 is a deficient number, since it is larger than the sum of its proper divisors (10504141220).

21008282434 is a wasteful number, since it uses less digits than its factorization.

21008282434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10504141219.

The product of its (nonzero) digits is 24576, while the sum is 34.

The spelling of 21008282434 in words is "twenty-one billion, eight million, two hundred eighty-two thousand, four hundred thirty-four".