1821274249 has 2 divisors, whose sum is σ = 1821274250. Its totient is φ = 1821274248.

The previous prime is 1821274187. The next prime is 1821274253. The reversal of 1821274249 is 9424721281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1117698624 + 703575625 = 33432^2 + 26525^2 .

It is a cyclic number.

It is not a de Polignac number, because 1821274249 - 2⁷ = 1821274121 is a prime.

It is not a weakly prime, because it can be changed into another prime (1821274289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910637124 + 910637125.

It is an arithmetic number, because the mean of its divisors is an integer number (910637125).

Almost surely, 2^1821274249 is an apocalyptic number.

It is an amenable number.

1821274249 is a deficient number, since it is larger than the sum of its proper divisors (1).

1821274249 is an equidigital number, since it uses as much as digits as its factorization.

1821274249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64512, while the sum is 40.

The square root of 1821274249 is about 42676.3898309124. The cubic root of 1821274249 is about 1221.2140224219.

The spelling of 1821274249 in words is "one billion, eight hundred twenty-one million, two hundred seventy-four thousand, two hundred forty-nine".