21583777834 has 4 divisors (see below), whose sum is σ = 32375666754. Its totient is φ = 10791888916.

The previous prime is 21583777819. The next prime is 21583777843. The reversal of 21583777834 is 43877738512.

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., 21011372209 + 572405625 = 144953^2 + 23925^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5395944457 + ... + 5395944460.

Almost surely, 2^21583777834 is an apocalyptic number.

21583777834 is a deficient number, since it is larger than the sum of its proper divisors (10791888920).

21583777834 is a wasteful number, since it uses less digits than its factorization.

21583777834 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10791888919.

The product of its digits is 7902720, while the sum is 55.

The spelling of 21583777834 in words is "twenty-one billion, five hundred eighty-three million, seven hundred seventy-seven thousand, eight hundred thirty-four".