102102021 has 12 divisors (see below), whose sum is σ = 168549472. Its totient is φ = 58343976.

The previous prime is 102102019. The next prime is 102102041. The reversal of 102102021 is 120201201.

It is not a de Polignac number, because 102102021 - 2¹ = 102102019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 102101994 and 102102012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102102041) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 810271 + ... + 810396.

Almost surely, 2^102102021 is an apocalyptic number.

It is an amenable number.

102102021 is a deficient number, since it is larger than the sum of its proper divisors (66447451).

102102021 is a wasteful number, since it uses less digits than its factorization.

102102021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1620680 (or 1620677 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 102102021 is about 10104.5544681594. The cubic root of 102102021 is about 467.3885972842.

Adding to 102102021 its reverse (120201201), we get a palindrome (222303222).

The spelling of 102102021 in words is "one hundred two million, one hundred two thousand, twenty-one".