21773443578 has 32 divisors (see below), whose sum is σ = 44542803840. Its totient is φ = 7093344960.

The previous prime is 21773443577. The next prime is 21773443621. The reversal of 21773443578 is 87534437712.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21773443578.

It is not an unprimeable number, because it can be changed into a prime (21773443577) 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 15 ways as a sum of consecutive naturals, for example, 131998 + ... + 246921.

It is an arithmetic number, because the mean of its divisors is an integer number (1391962620).

Almost surely, 2^21773443578 is an apocalyptic number.

21773443578 is an abundant number, since it is smaller than the sum of its proper divisors (22769360262).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21773443578 is a wasteful number, since it uses less digits than its factorization.

21773443578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379142.

The product of its digits is 3951360, while the sum is 51.

The spelling of 21773443578 in words is "twenty-one billion, seven hundred seventy-three million, four hundred forty-three thousand, five hundred seventy-eight".