20216387 has 2 divisors, whose sum is σ = 20216388. Its totient is φ = 20216386.

The previous prime is 20216369. The next prime is 20216411. The reversal of 20216387 is 78361202.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20216387 is a prime.

It is a Chen prime.

It is a zygodrome in base 7.

It is not a weakly prime, because it can be changed into another prime (20216347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10108193 + 10108194.

It is an arithmetic number, because the mean of its divisors is an integer number (10108194).

Almost surely, 2^20216387 is an apocalyptic number.

20216387 is a deficient number, since it is larger than the sum of its proper divisors (1).

20216387 is an equidigital number, since it uses as much as digits as its factorization.

20216387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 20216387 is about 4496.2636710940. The cubic root of 20216387 is about 272.4171933677.

Adding to 20216387 its reverse (78361202), we get a palindrome (98577589).

The spelling of 20216387 in words is "twenty million, two hundred sixteen thousand, three hundred eighty-seven".