1811471997825 has 336 divisors, whose sum is σ = 4012545212416. Its totient is φ = 793429603200.

The previous prime is 1811471997823. The next prime is 1811471997851. The reversal of 1811471997825 is 5287991741181.

1811471997825 is a `hidden beast` number, since 1 + 8 + 1 + 1 + 471 + 99 + 78 + 2 + 5 = 666.

It is not a de Polignac number, because 1811471997825 - 2¹ = 1811471997823 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (1811471997823) by changing a digit.

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 335 ways as a sum of consecutive naturals, for example, 407344752 + ... + 407349198.

Almost surely, 2^{1811471997825} is an apocalyptic number.

1811471997825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1811471997825 is an abundant number, since it is smaller than the sum of its proper divisors (2201073214591).

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

1811471997825 is a wasteful number, since it uses less digits than its factorization.

1811471997825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4616 (or 4596 counting only the distinct ones).

The product of its digits is 10160640, while the sum is 63.

The spelling of 1811471997825 in words is "one trillion, eight hundred eleven billion, four hundred seventy-one million, nine hundred ninety-seven thousand, eight hundred twenty-five".