1021991347144 has 32 divisors (see below), whose sum is σ = 1984624270200. Its totient is φ = 492799336960.

The previous prime is 1021991347121. The next prime is 1021991347151. The reversal of 1021991347144 is 4417431991201.

It can be written as a sum of positive squares in 4 ways, for example, as 1014375294244 + 7616052900 = 1007162^2 + 87270^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1021991347094 and 1021991347103.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2371267 + ... + 2768914.

Almost surely, 2^{1021991347144} is an apocalyptic number.

It is an amenable number.

1021991347144 is a deficient number, since it is larger than the sum of its proper divisors (962632923056).

1021991347144 is a wasteful number, since it uses less digits than its factorization.

1021991347144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5141073 (or 5141069 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 46.

The spelling of 1021991347144 in words is "one trillion, twenty-one billion, nine hundred ninety-one million, three hundred forty-seven thousand, one hundred forty-four".