102821025 has 24 divisors (see below), whose sum is σ = 170614080. Its totient is φ = 54639040.

The previous prime is 102821021. The next prime is 102821029. The reversal of 102821025 is 520128201.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (102821021) and next prime (102821029).

It is not a de Polignac number, because 102821025 - 2² = 102821021 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 102820992 and 102821010.

It is not an unprimeable number, because it can be changed into a prime (102821021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19636 + ... + 24314.

It is an arithmetic number, because the mean of its divisors is an integer number (7108920).

Almost surely, 2^102821025 is an apocalyptic number.

102821025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

102821025 is a deficient number, since it is larger than the sum of its proper divisors (67793055).

102821025 is a wasteful number, since it uses less digits than its factorization.

102821025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4985 (or 4980 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 102821025 is about 10140.0702660287. The cubic root of 102821025 is about 468.4831512290.

Adding to 102821025 its reverse (520128201), we get a palindrome (622949226).

The spelling of 102821025 in words is "one hundred two million, eight hundred twenty-one thousand, twenty-five".