20306987 has 2 divisors, whose sum is σ = 20306988. Its totient is φ = 20306986.

The previous prime is 20306977. The next prime is 20307037. The reversal of 20306987 is 78960302.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20306987 - 2⁴ = 20306971 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20306977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10153493 + 10153494.

It is an arithmetic number, because the mean of its divisors is an integer number (10153494).

Almost surely, 2^20306987 is an apocalyptic number.

20306987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20306987 is an equidigital number, since it uses as much as digits as its factorization.

20306987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 20306987 is about 4506.3274403887. The cubic root of 20306987 is about 272.8235340232.

The spelling of 20306987 in words is "twenty million, three hundred six thousand, nine hundred eighty-seven".