21022201987 has 2 divisors, whose sum is σ = 21022201988. Its totient is φ = 21022201986.

The previous prime is 21022201973. The next prime is 21022202021. The reversal of 21022201987 is 78910222012.

It is an a-pointer prime, because the next prime (21022202021) can be obtained adding 21022201987 to its sum of digits (34).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21022201987 is a prime.

It is not a weakly prime, because it can be changed into another prime (21022201927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10511100993 + 10511100994.

It is an arithmetic number, because the mean of its divisors is an integer number (10511100994).

Almost surely, 2^21022201987 is an apocalyptic number.

21022201987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21022201987 is an equidigital number, since it uses as much as digits as its factorization.

21022201987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 34.

Adding to 21022201987 its reverse (78910222012), we get a palindrome (99932423999).

The spelling of 21022201987 in words is "twenty-one billion, twenty-two million, two hundred one thousand, nine hundred eighty-seven".