1812121740 has 384 divisors, whose sum is σ = 6846013440. Its totient is φ = 391910400.

The previous prime is 1812121691. The next prime is 1812121741. The reversal of 1812121740 is 471212181.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1812121741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2393442 + ... + 2394198.

It is an arithmetic number, because the mean of its divisors is an integer number (17828160).

Almost surely, 2^1812121740 is an apocalyptic number.

1812121740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1812121740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3423006720).

1812121740 is an abundant number, since it is smaller than the sum of its proper divisors (5033891700).

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

1812121740 is a wasteful number, since it uses less digits than its factorization.

1812121740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830 (or 822 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 1812121740 is about 42569.0232446083. The cubic root of 1812121740 is about 1219.1649171891.

The spelling of 1812121740 in words is "one billion, eight hundred twelve million, one hundred twenty-one thousand, seven hundred forty".