21201011087 has 2 divisors, whose sum is σ = 21201011088. Its totient is φ = 21201011086.

The previous prime is 21201011003. The next prime is 21201011141. The reversal of 21201011087 is 78011010212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201011087 is a prime.

It is a super-2 number, since 2×21201011087² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201011387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600505543 + 10600505544.

It is an arithmetic number, because the mean of its divisors is an integer number (10600505544).

Almost surely, 2^21201011087 is an apocalyptic number.

21201011087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201011087 is an equidigital number, since it uses as much as digits as its factorization.

21201011087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 23.

Adding to 21201011087 its reverse (78011010212), we get a palindrome (99212021299).

The spelling of 21201011087 in words is "twenty-one billion, two hundred one million, eleven thousand, eighty-seven".