21249784353 has 16 divisors (see below), whose sum is σ = 32385133440. Its totient is φ = 12141042816.

The previous prime is 21249784351. The next prime is 21249784379. The reversal of 21249784353 is 35348794212.

It is not a de Polignac number, because 21249784353 - 2¹ = 21249784351 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21249784351) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92701 + ... + 226037.

It is an arithmetic number, because the mean of its divisors is an integer number (2024070840).

Almost surely, 2^21249784353 is an apocalyptic number.

It is an amenable number.

21249784353 is a deficient number, since it is larger than the sum of its proper divisors (11135349087).

21249784353 is a wasteful number, since it uses less digits than its factorization.

21249784353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140936.

The product of its digits is 1451520, while the sum is 48.

The spelling of 21249784353 in words is "twenty-one billion, two hundred forty-nine million, seven hundred eighty-four thousand, three hundred fifty-three".