1820007997 has 4 divisors (see below), whose sum is σ = 1820104000. Its totient is φ = 1819911996.

The previous prime is 1820007979. The next prime is 1820008019. The reversal of 1820007997 is 7997000281.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 7997000281 = 31 ⋅257967751.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1820007997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820007977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9003 + ... + 61000.

It is an arithmetic number, because the mean of its divisors is an integer number (455026000).

Almost surely, 2^1820007997 is an apocalyptic number.

It is an amenable number.

1820007997 is a deficient number, since it is larger than the sum of its proper divisors (96003).

1820007997 is an equidigital number, since it uses as much as digits as its factorization.

1820007997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96002.

The product of its (nonzero) digits is 63504, while the sum is 43.

The square root of 1820007997 is about 42661.5517415858. The cubic root of 1820007997 is about 1220.9309379805.

The spelling of 1820007997 in words is "one billion, eight hundred twenty million, seven thousand, nine hundred ninety-seven".