20359987 has 2 divisors, whose sum is σ = 20359988.
Its totient is φ = 20359986.
The previous prime is 20359961. The next prime is 20359993. The reversal of 20359987 is 78995302.
It is a happy number.
It is a strong prime.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-20359987 is a prime.
It is not a weakly prime, because it can be changed into another prime (20359957) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10179993 + 10179994.
It is an arithmetic number, because the mean of its divisors is an integer number (10179994).
Almost surely, 220359987 is an apocalyptic number.
20359987 is a deficient number, since it is larger than the sum of its proper divisors (1).
20359987 is an equidigital number, since it uses as much as digits as its factorization.
20359987 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 136080, while the sum is 43.
The square root of 20359987 is about 4512.2042285340.
The cubic root of 20359987 is about 273.0606787706.
The spelling of 20359987 in words is "twenty million, three hundred fifty-nine thousand, nine hundred eighty-seven".