1820472917 has 2 divisors, whose sum is σ = 1820472918. Its totient is φ = 1820472916.

The previous prime is 1820472887. The next prime is 1820472937. The reversal of 1820472917 is 7192740281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1657629796 + 162843121 = 40714^2 + 12761^2 .

It is an emirp because it is prime and its reverse (7192740281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1820472917 - 2¹² = 1820468821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1820472937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910236458 + 910236459.

It is an arithmetic number, because the mean of its divisors is an integer number (910236459).

Almost surely, 2^1820472917 is an apocalyptic number.

It is an amenable number.

1820472917 is a deficient number, since it is larger than the sum of its proper divisors (1).

1820472917 is an equidigital number, since it uses as much as digits as its factorization.

1820472917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56448, while the sum is 41.

The square root of 1820472917 is about 42667.0003281224. Note that the first 3 decimals coincide. The cubic root of 1820472917 is about 1221.0348911656.

The spelling of 1820472917 in words is "one billion, eight hundred twenty million, four hundred seventy-two thousand, nine hundred seventeen".