20651887 has 2 divisors, whose sum is σ = 20651888. Its totient is φ = 20651886.

The previous prime is 20651881. The next prime is 20651893. The reversal of 20651887 is 78815602.

It is a balanced prime because it is at equal distance from previous prime (20651881) and next prime (20651893).

It is a cyclic number.

It is not a de Polignac number, because 20651887 - 2⁷ = 20651759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20651881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10325943 + 10325944.

It is an arithmetic number, because the mean of its divisors is an integer number (10325944).

Almost surely, 2^20651887 is an apocalyptic number.

20651887 is a deficient number, since it is larger than the sum of its proper divisors (1).

20651887 is an equidigital number, since it uses as much as digits as its factorization.

20651887 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 20651887 is about 4544.4347283243. The cubic root of 20651887 is about 274.3594435480.

The spelling of 20651887 in words is "twenty million, six hundred fifty-one thousand, eight hundred eighty-seven".