181008290920 has 16 divisors (see below), whose sum is σ = 407268654660. Its totient is φ = 72403316352.

The previous prime is 181008290909. The next prime is 181008290923. The reversal of 181008290920 is 29092800181.

It can be written as a sum of positive squares in 2 ways, for example, as 181004298916 + 3992004 = 425446^2 + 1998^2 .

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 4525207273 = 181008290920 / (1 + 8 + 1 + 0 + 0 + 8 + 2 + 9 + 0 + 9 + 2 + 0).

It is not an unprimeable number, because it can be changed into a prime (181008290923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2262603597 + ... + 2262603676.

Almost surely, 2^181008290920 is an apocalyptic number.

181008290920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

181008290920 is an abundant number, since it is smaller than the sum of its proper divisors (226260363740).

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

181008290920 is a wasteful number, since it uses less digits than its factorization.

181008290920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4525207284 (or 4525207280 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 40.

The spelling of 181008290920 in words is "one hundred eighty-one billion, eight million, two hundred ninety thousand, nine hundred twenty".