215500001 has 2 divisors, whose sum is σ = 215500002. Its totient is φ = 215500000.

The previous prime is 215499983. The next prime is 215500039. The reversal of 215500001 is 100005512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 184307776 + 31192225 = 13576^2 + 5585^2 .

It is a cyclic number.

It is not a de Polignac number, because 215500001 - 2¹⁸ = 215237857 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (215500801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107750000 + 107750001.

It is an arithmetic number, because the mean of its divisors is an integer number (107750001).

Almost surely, 2^215500001 is an apocalyptic number.

It is an amenable number.

215500001 is a deficient number, since it is larger than the sum of its proper divisors (1).

215500001 is an equidigital number, since it uses as much as digits as its factorization.

215500001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 50, while the sum is 14.

The square root of 215500001 is about 14679.9182899633. The cubic root of 215500001 is about 599.5366802798.

Adding to 215500001 its reverse (100005512), we get a palindrome (315505513).

The spelling of 215500001 in words is "two hundred fifteen million, five hundred thousand, one".