1902181009 has 2 divisors, whose sum is σ = 1902181010. Its totient is φ = 1902181008.

The previous prime is 1902180979. The next prime is 1902181027. The reversal of 1902181009 is 9001812091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1226960784 + 675220225 = 35028^2 + 25985^2 .

It is an emirp because it is prime and its reverse (9001812091) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1902181009 is a prime.

It is not a weakly prime, because it can be changed into another prime (1902181109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 951090504 + 951090505.

It is an arithmetic number, because the mean of its divisors is an integer number (951090505).

Almost surely, 2^1902181009 is an apocalyptic number.

It is an amenable number.

1902181009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1902181009 is an equidigital number, since it uses as much as digits as its factorization.

1902181009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 31.

The square root of 1902181009 is about 43614.0001490347. Note that the first 3 decimals coincide. The cubic root of 1902181009 is about 1239.0360634256.

The spelling of 1902181009 in words is "one billion, nine hundred two million, one hundred eighty-one thousand, nine".