21201112087 has 2 divisors, whose sum is σ = 21201112088. Its totient is φ = 21201112086.

The previous prime is 21201112081. The next prime is 21201112139. The reversal of 21201112087 is 78021110212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21201112087 - 2³¹ = 19053628439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201112081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600556043 + 10600556044.

It is an arithmetic number, because the mean of its divisors is an integer number (10600556044).

Almost surely, 2^21201112087 is an apocalyptic number.

21201112087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201112087 is an equidigital number, since it uses as much as digits as its factorization.

21201112087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 25.

Adding to 21201112087 its reverse (78021110212), we get a palindrome (99222222299).

The spelling of 21201112087 in words is "twenty-one billion, two hundred one million, one hundred twelve thousand, eighty-seven".