102508821 has 12 divisors (see below), whose sum is σ = 153552672. Its totient is φ = 68339052.

The previous prime is 102508817. The next prime is 102508829. The reversal of 102508821 is 128805201.

It is not a de Polignac number, because 102508821 - 2² = 102508817 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102508829) 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 11 ways as a sum of consecutive naturals, for example, 210681 + ... + 211166.

It is an arithmetic number, because the mean of its divisors is an integer number (12796056).

Almost surely, 2^102508821 is an apocalyptic number.

It is an amenable number.

102508821 is a deficient number, since it is larger than the sum of its proper divisors (51043851).

102508821 is an frugal number, since it uses more digits than its factorization.

102508821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421862 (or 421850 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 102508821 is about 10124.6639944247. The cubic root of 102508821 is about 468.0085057626.

The spelling of 102508821 in words is "one hundred two million, five hundred eight thousand, eight hundred twenty-one".