21082749601 has 27 divisors (see below), whose sum is σ = 22630605361. Its totient is φ = 19639035944.

The previous prime is 21082749599. The next prime is 21082749617. The reversal of 21082749601 is 10694728012.

The square root of 21082749601 is 145199.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 21082749601 - 2¹ = 21082749599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21082743601) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 197034990 + ... + 197035096.

Almost surely, 2^21082749601 is an apocalyptic number.

21082749601 is the 145199-th square number.

21082749601 is the 72600-th centered octagonal number.

It is an amenable number.

21082749601 is a deficient number, since it is larger than the sum of its proper divisors (1547855760).

21082749601 is an frugal number, since it uses more digits than its factorization.

21082749601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378 (or 189 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 40.

The spelling of 21082749601 in words is "twenty-one billion, eighty-two million, seven hundred forty-nine thousand, six hundred one".