102521221 has 4 divisors (see below), whose sum is σ = 111841344. Its totient is φ = 93201100.

The previous prime is 102521213. The next prime is 102521227. The reversal of 102521221 is 122125201.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 102521221 - 2³ = 102521213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 102521195 and 102521204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102521227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4660045 + ... + 4660066.

It is an arithmetic number, because the mean of its divisors is an integer number (27960336).

Almost surely, 2^102521221 is an apocalyptic number.

102521221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

102521221 is a deficient number, since it is larger than the sum of its proper divisors (9320123).

102521221 is an equidigital number, since it uses as much as digits as its factorization.

102521221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9320122.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 102521221 is about 10125.2763419079. The cubic root of 102521221 is about 468.0273759158.

Adding to 102521221 its reverse (122125201), we get a palindrome (224646422).

The spelling of 102521221 in words is "one hundred two million, five hundred twenty-one thousand, two hundred twenty-one".