20653987 has 2 divisors, whose sum is σ = 20653988. Its totient is φ = 20653986.

The previous prime is 20653981. The next prime is 20653993. The reversal of 20653987 is 78935602.

It is a balanced prime because it is at equal distance from previous prime (20653981) and next prime (20653993).

It is a cyclic number.

It is not a de Polignac number, because 20653987 - 2³ = 20653979 is a prime.

It is not a weakly prime, because it can be changed into another prime (20653981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10326993 + 10326994.

It is an arithmetic number, because the mean of its divisors is an integer number (10326994).

Almost surely, 2^20653987 is an apocalyptic number.

20653987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20653987 is an equidigital number, since it uses as much as digits as its factorization.

20653987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 20653987 is about 4544.6657742897. The cubic root of 20653987 is about 274.3687427032.

The spelling of 20653987 in words is "twenty million, six hundred fifty-three thousand, nine hundred eighty-seven".