1820252491 has 2 divisors, whose sum is σ = 1820252492. Its totient is φ = 1820252490.

The previous prime is 1820252471. The next prime is 1820252501. The reversal of 1820252491 is 1942520281.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1820252491 - 2¹³ = 1820244299 is a prime.

It is not a weakly prime, because it can be changed into another prime (1820252411) 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 as a sum of consecutive naturals, namely, 910126245 + 910126246.

It is an arithmetic number, because the mean of its divisors is an integer number (910126246).

Almost surely, 2^1820252491 is an apocalyptic number.

1820252491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1820252491 is an equidigital number, since it uses as much as digits as its factorization.

1820252491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 1820252491 is about 42664.4171529391. The cubic root of 1820252491 is about 1220.9856075064.

The spelling of 1820252491 in words is "one billion, eight hundred twenty million, two hundred fifty-two thousand, four hundred ninety-one".