22782581721 has 45 divisors (see below), whose sum is σ = 35231623119. Its totient is φ = 14671270800.

The previous prime is 22782581719. The next prime is 22782581741. The reversal of 22782581721 is 12718528722.

The square root of 22782581721 is 150939.

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

22782581721 is a `hidden beast` number, since 227 + 8 + 258 + 172 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 9051429321 + 13731152400 = 95139^2 + 117180^2 .

It is not a de Polignac number, because 22782581721 - 2¹ = 22782581719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (22782581741) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 42111711 + ... + 42112251.

Almost surely, 2^22782581721 is an apocalyptic number.

22782581721 is the 150939-th square number.

22782581721 is the 75470-th centered octagonal number.

It is an amenable number.

22782581721 is a deficient number, since it is larger than the sum of its proper divisors (12449041398).

22782581721 is an frugal number, since it uses more digits than its factorization.

22782581721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1156 (or 575 counting only the distinct ones).

The product of its digits is 250880, while the sum is 45.

The spelling of 22782581721 in words is "twenty-two billion, seven hundred eighty-two million, five hundred eighty-one thousand, seven hundred twenty-one".