102020821 has 8 divisors (see below), whose sum is σ = 117149504. Its totient is φ = 87030720.

The previous prime is 102020819. The next prime is 102020873. The reversal of 102020821 is 128020201.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 102020821 - 2¹ = 102020819 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 102020795 and 102020804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102020881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33060 + ... + 36013.

It is an arithmetic number, because the mean of its divisors is an integer number (14643688).

Almost surely, 2^102020821 is an apocalyptic number.

It is an amenable number.

102020821 is a deficient number, since it is larger than the sum of its proper divisors (15128683).

102020821 is an equidigital number, since it uses as much as digits as its factorization.

102020821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69291.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 102020821 is about 10100.5356788638. The cubic root of 102020821 is about 467.2646623577.

The spelling of 102020821 in words is "one hundred two million, twenty thousand, eight hundred twenty-one".