102000021 has 8 divisors (see below), whose sum is σ = 136835040. Its totient is φ = 67582512.

The previous prime is 101999969. The next prime is 102000023. The reversal of 102000021 is 120000201.

It is a happy number.

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

It is not a de Polignac number, because 102000021 - 2¹⁵ = 101967253 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 101999973 and 102000009.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102000023) 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, 103806 + ... + 104783.

It is an arithmetic number, because the mean of its divisors is an integer number (17104380).

Almost surely, 2^102000021 is an apocalyptic number.

It is an amenable number.

102000021 is a deficient number, since it is larger than the sum of its proper divisors (34835019).

102000021 is a wasteful number, since it uses less digits than its factorization.

102000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208755.

The product of its (nonzero) digits is 4, while the sum is 6.

The square root of 102000021 is about 10099.5059780169. The cubic root of 102000021 is about 467.2329049005.

Adding to 102000021 its reverse (120000201), we get a palindrome (222000222).

The spelling of 102000021 in words is "one hundred two million, twenty-one", and thus it is an aban number.