1643245122440 has 32 divisors (see below), whose sum is σ = 3701247502680. Its totient is φ = 656596541952.

The previous prime is 1643245122439. The next prime is 1643245122473. The reversal of 1643245122440 is 442215423461.

It can be written as a sum of positive squares in 4 ways, for example, as 1412109175684 + 231135946756 = 1188322^2 + 480766^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1643245122394 and 1643245122403.

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, 21884147 + ... + 21959106.

Almost surely, 2^{1643245122440} is an apocalyptic number.

1643245122440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1643245122440 is an abundant number, since it is smaller than the sum of its proper divisors (2058002380240).

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

1643245122440 is a wasteful number, since it uses less digits than its factorization.

1643245122440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43844201 (or 43844197 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 38.

The spelling of 1643245122440 in words is "one trillion, six hundred forty-three billion, two hundred forty-five million, one hundred twenty-two thousand, four hundred forty".