1821038138400 has 216 divisors, whose sum is σ = 6418514345040. Its totient is φ = 448255441920.

The previous prime is 1821038138399. The next prime is 1821038138401. The reversal of 1821038138400 is 48318301281.

It is an interprime number because it is at equal distance from previous prime (1821038138399) and next prime (1821038138401).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (1821038138401) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1839270 + ... + 2650469.

It is an arithmetic number, because the mean of its divisors is an integer number (29715344190).

Almost surely, 2^{1821038138400} is an apocalyptic number.

1821038138400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1821038138400 is an abundant number, since it is smaller than the sum of its proper divisors (4597476206640).

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

1821038138400 is a wasteful number, since it uses less digits than its factorization.

1821038138400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4489788 (or 4489762 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 39.

The spelling of 1821038138400 in words is "one trillion, eight hundred twenty-one billion, thirty-eight million, one hundred thirty-eight thousand, four hundred".