20739287 has 4 divisors (see below), whose sum is σ = 21221640. Its totient is φ = 20256936.

The previous prime is 20739283. The next prime is 20739343. The reversal of 20739287 is 78293702.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20739287 - 2² = 20739283 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20739287.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20739283) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 241112 + ... + 241197.

It is an arithmetic number, because the mean of its divisors is an integer number (5305410).

Almost surely, 2^20739287 is an apocalyptic number.

20739287 is a deficient number, since it is larger than the sum of its proper divisors (482353).

20739287 is an equidigital number, since it uses as much as digits as its factorization.

20739287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482352.

The product of its (nonzero) digits is 42336, while the sum is 38.

The square root of 20739287 is about 4554.0407332390. The cubic root of 20739287 is about 274.7459339416.

The spelling of 20739287 in words is "twenty million, seven hundred thirty-nine thousand, two hundred eighty-seven".