22440720781 has 4 divisors (see below), whose sum is σ = 22441128732. Its totient is φ = 22440312832.

The previous prime is 22440720767. The next prime is 22440720793. The reversal of 22440720781 is 18702704422.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18702704422 = 2 ⋅9351352211.

It can be written as a sum of positive squares in 2 ways, for example, as 20652276681 + 1788444100 = 143709^2 + 42290^2 .

It is a cyclic number.

It is not a de Polignac number, because 22440720781 - 2¹⁵ = 22440688013 is a prime.

It is a super-2 number, since 2×22440720781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 22440720781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22440720481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105670 + ... + 236743.

It is an arithmetic number, because the mean of its divisors is an integer number (5610282183).

Almost surely, 2^22440720781 is an apocalyptic number.

It is an amenable number.

22440720781 is a deficient number, since it is larger than the sum of its proper divisors (407951).

22440720781 is an equidigital number, since it uses as much as digits as its factorization.

22440720781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407950.

The product of its (nonzero) digits is 50176, while the sum is 37.

The spelling of 22440720781 in words is "twenty-two billion, four hundred forty million, seven hundred twenty thousand, seven hundred eighty-one".