20578747 has 4 divisors (see below), whose sum is σ = 23518576. Its totient is φ = 17638920.

The previous prime is 20578741. The next prime is 20578751. The reversal of 20578747 is 74787502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74787502 = 2 ⋅37393751.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20578747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20578741) 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, 1469904 + ... + 1469917.

It is an arithmetic number, because the mean of its divisors is an integer number (5879644).

Almost surely, 2^20578747 is an apocalyptic number.

20578747 is a deficient number, since it is larger than the sum of its proper divisors (2939829).

20578747 is an equidigital number, since it uses as much as digits as its factorization.

20578747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2939828.

The product of its (nonzero) digits is 109760, while the sum is 40.

The square root of 20578747 is about 4536.3803852852. The cubic root of 20578747 is about 274.0351731713.

The spelling of 20578747 in words is "twenty million, five hundred seventy-eight thousand, seven hundred forty-seven".