102315821 has 2 divisors, whose sum is σ = 102315822. Its totient is φ = 102315820.

The previous prime is 102315797. The next prime is 102315907. The reversal of 102315821 is 128513201.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 93818596 + 8497225 = 9686^2 + 2915^2 .

It is an emirp because it is prime and its reverse (128513201) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-102315821 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102315721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51157910 + 51157911.

It is an arithmetic number, because the mean of its divisors is an integer number (51157911).

Almost surely, 2^102315821 is an apocalyptic number.

It is an amenable number.

102315821 is a deficient number, since it is larger than the sum of its proper divisors (1).

102315821 is an equidigital number, since it uses as much as digits as its factorization.

102315821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 102315821 is about 10115.1283234569. The cubic root of 102315821 is about 467.7146045893.

The spelling of 102315821 in words is "one hundred two million, three hundred fifteen thousand, eight hundred twenty-one".