1821155478472 has 64 divisors (see below), whose sum is σ = 3788645400000. Its totient is φ = 813677786880.

The previous prime is 1821155478463. The next prime is 1821155478481. The reversal of 1821155478472 is 2748745511281.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1821155478463) and next prime (1821155478481).

It is an unprimeable number.

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, 75526354 + ... + 75550462.

It is an arithmetic number, because the mean of its divisors is an integer number (59197584375).

Almost surely, 2^{1821155478472} is an apocalyptic number.

It is an amenable number.

1821155478472 is an abundant number, since it is smaller than the sum of its proper divisors (1967489921528).

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

1821155478472 is a wasteful number, since it uses less digits than its factorization.

1821155478472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38734 (or 38730 counting only the distinct ones).

The product of its digits is 5017600, while the sum is 55.

The spelling of 1821155478472 in words is "one trillion, eight hundred twenty-one billion, one hundred fifty-five million, four hundred seventy-eight thousand, four hundred seventy-two".