1820521125 has 24 divisors (see below), whose sum is σ = 3281794776. Its totient is φ = 970944000.

The previous prime is 1820521117. The next prime is 1820521133. The reversal of 1820521125 is 5211250281.

It is a happy number.

1820521125 is a `hidden beast` number, since 18 + 2 + 0 + 521 + 125 = 666.

It is an interprime number because it is at equal distance from previous prime (1820521117) and next prime (1820521133).

It can be written as a sum of positive squares in 4 ways, for example, as 581340321 + 1239180804 = 24111^2 + 35202^2 .

It is not a de Polignac number, because 1820521125 - 2³ = 1820521117 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 807996 + ... + 810245.

It is an arithmetic number, because the mean of its divisors is an integer number (136741449).

Almost surely, 2^1820521125 is an apocalyptic number.

1820521125 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1820521125 is a deficient number, since it is larger than the sum of its proper divisors (1461273651).

1820521125 is a wasteful number, since it uses less digits than its factorization.

1820521125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1618262 (or 1618249 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

The square root of 1820521125 is about 42667.5652574646. The cubic root of 1820521125 is about 1221.0456691581.

The spelling of 1820521125 in words is "one billion, eight hundred twenty million, five hundred twenty-one thousand, one hundred twenty-five".