100102021 has 2 divisors, whose sum is σ = 100102022. Its totient is φ = 100102020.

The previous prime is 100102019. The next prime is 100102027. The reversal of 100102021 is 120201001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80299521 + 19802500 = 8961^2 + 4450^2 .

It is a cyclic number.

It is not a de Polignac number, because 100102021 - 2¹ = 100102019 is a prime.

Together with 100102019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 100101995 and 100102013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100102027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50051010 + 50051011.

It is an arithmetic number, because the mean of its divisors is an integer number (50051011).

Almost surely, 2^100102021 is an apocalyptic number.

It is an amenable number.

100102021 is a deficient number, since it is larger than the sum of its proper divisors (1).

100102021 is an equidigital number, since it uses as much as digits as its factorization.

100102021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 100102021 is about 10005.0997496277. The cubic root of 100102021 is about 464.3166762243.

Adding to 100102021 its reverse (120201001), we get a palindrome (220303022).

The spelling of 100102021 in words is "one hundred million, one hundred two thousand, twenty-one".