2221978859981 has 32 divisors (see below), whose sum is σ = 2371571485920. Its totient is φ = 2078054809600.

The previous prime is 2221978859897. The next prime is 2221978859987. The reversal of 2221978859981 is 1899588791222.

It can be written as a sum of positive squares in 16 ways, for example, as 1410313004356 + 811665855625 = 1187566^2 + 900925^2 .

It is not a de Polignac number, because 2221978859981 - 2¹⁴ = 2221978843597 is a prime.

It is a super-2 number, since 2×2221978859981² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2221978859987) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 97782701 + ... + 97805421.

It is an arithmetic number, because the mean of its divisors is an integer number (74111608935).

Almost surely, 2^{2221978859981} is an apocalyptic number.

It is an amenable number.

2221978859981 is a deficient number, since it is larger than the sum of its proper divisors (149592625939).

2221978859981 is a wasteful number, since it uses less digits than its factorization.

2221978859981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23377.

The product of its digits is 104509440, while the sum is 71.

The spelling of 2221978859981 in words is "two trillion, two hundred twenty-one billion, nine hundred seventy-eight million, eight hundred fifty-nine thousand, nine hundred eighty-one".