1821368149 has 2 divisors, whose sum is σ = 1821368150. Its totient is φ = 1821368148.

The previous prime is 1821368123. The next prime is 1821368167. The reversal of 1821368149 is 9418631281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1448183025 + 373185124 = 38055^2 + 19318^2 .

It is a cyclic number.

It is not a de Polignac number, because 1821368149 - 2²⁵ = 1787813717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1821368119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910684074 + 910684075.

It is an arithmetic number, because the mean of its divisors is an integer number (910684075).

Almost surely, 2^1821368149 is an apocalyptic number.

It is an amenable number.

1821368149 is a deficient number, since it is larger than the sum of its proper divisors (1).

1821368149 is an equidigital number, since it uses as much as digits as its factorization.

1821368149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 43.

The square root of 1821368149 is about 42677.4899566504. The cubic root of 1821368149 is about 1221.2350095643.

The spelling of 1821368149 in words is "one billion, eight hundred twenty-one million, three hundred sixty-eight thousand, one hundred forty-nine".