1812561938 has 16 divisors (see below), whose sum is σ = 3003557760. Its totient is φ = 813462000.

The previous prime is 1812561931. The next prime is 1812561941. The reversal of 1812561938 is 8391652181.

It is not an unprimeable number, because it can be changed into a prime (1812561931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 519713 + ... + 523188.

It is an arithmetic number, because the mean of its divisors is an integer number (187722360).

Almost surely, 2^1812561938 is an apocalyptic number.

1812561938 is a deficient number, since it is larger than the sum of its proper divisors (1190995822).

1812561938 is a wasteful number, since it uses less digits than its factorization.

1812561938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1042993.

The product of its digits is 103680, while the sum is 44.

The square root of 1812561938 is about 42574.1933335207. The cubic root of 1812561938 is about 1219.2636284578.

The spelling of 1812561938 in words is "one billion, eight hundred twelve million, five hundred sixty-one thousand, nine hundred thirty-eight".