20221987 has 2 divisors, whose sum is σ = 20221988. Its totient is φ = 20221986.

The previous prime is 20221969. The next prime is 20222003. The reversal of 20221987 is 78912202.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20221987 - 2¹¹ = 20219939 is a prime.

It is not a weakly prime, because it can be changed into another prime (20221937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10110993 + 10110994.

It is an arithmetic number, because the mean of its divisors is an integer number (10110994).

Almost surely, 2^20221987 is an apocalyptic number.

20221987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20221987 is an equidigital number, since it uses as much as digits as its factorization.

20221987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 20221987 is about 4496.8863672546. The cubic root of 20221987 is about 272.4423445061.

The spelling of 20221987 in words is "twenty million, two hundred twenty-one thousand, nine hundred eighty-seven".