1994894520381 has 72 divisors (see below), whose sum is σ = 3597759415224. Its totient is φ = 1058187110400.

The previous prime is 1994894520373. The next prime is 1994894520383. The reversal of 1994894520381 is 1830254984991.

1994894520381 is a `hidden beast` number, since 1 + 99 + 489 + 45 + 20 + 3 + 8 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 976076817156 + 1018817703225 = 987966^2 + 1009365^2 .

It is not a de Polignac number, because 1994894520381 - 2³ = 1994894520373 is a prime.

It is a super-2 number, since 2×1994894520381² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1994894520383) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1275270 + ... + 2369831.

It is an arithmetic number, because the mean of its divisors is an integer number (49968880767).

Almost surely, 2^{1994894520381} is an apocalyptic number.

It is an amenable number.

1994894520381 is a deficient number, since it is larger than the sum of its proper divisors (1602864894843).

1994894520381 is a wasteful number, since it uses less digits than its factorization.

1994894520381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3645211 (or 3645201 counting only the distinct ones).

The product of its (nonzero) digits is 22394880, while the sum is 63.

The spelling of 1994894520381 in words is "one trillion, nine hundred ninety-four billion, eight hundred ninety-four million, five hundred twenty thousand, three hundred eighty-one".