20739387 has 4 divisors (see below), whose sum is σ = 27652520. Its totient is φ = 13826256.

The previous prime is 20739347. The next prime is 20739421. The reversal of 20739387 is 78393702.

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

It is not a de Polignac number, because 20739387 - 2¹⁰ = 20738363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20739347) 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, 3456562 + ... + 3456567.

It is an arithmetic number, because the mean of its divisors is an integer number (6913130).

Almost surely, 2^20739387 is an apocalyptic number.

20739387 is a deficient number, since it is larger than the sum of its proper divisors (6913133).

20739387 is an equidigital number, since it uses as much as digits as its factorization.

20739387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6913132.

The product of its (nonzero) digits is 63504, while the sum is 39.

The square root of 20739387 is about 4554.0517124864. The cubic root of 20739387 is about 274.7463755279.

The spelling of 20739387 in words is "twenty million, seven hundred thirty-nine thousand, three hundred eighty-seven".