1820855487 has 16 divisors (see below), whose sum is σ = 2673274752. Its totient is φ = 1093233120.

The previous prime is 1820855479. The next prime is 1820855503. The reversal of 1820855487 is 7845580281.

It is not a de Polignac number, because 1820855487 - 2³ = 1820855479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820855447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 254308 + ... + 261369.

It is an arithmetic number, because the mean of its divisors is an integer number (167079672).

Almost surely, 2^1820855487 is an apocalyptic number.

1820855487 is a deficient number, since it is larger than the sum of its proper divisors (852419265).

1820855487 is a wasteful number, since it uses less digits than its factorization.

1820855487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 515798.

The product of its (nonzero) digits is 716800, while the sum is 48.

The square root of 1820855487 is about 42671.4832997401. The cubic root of 1820855487 is about 1221.1204181360.

The spelling of 1820855487 in words is "one billion, eight hundred twenty million, eight hundred fifty-five thousand, four hundred eighty-seven".