20870147 has 4 divisors (see below), whose sum is σ = 20986920. Its totient is φ = 20753376.

The previous prime is 20870137. The next prime is 20870149. The reversal of 20870147 is 74107802.

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 20870147 - 2¹⁶ = 20804611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20870149) 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, 58118 + ... + 58475.

It is an arithmetic number, because the mean of its divisors is an integer number (5246730).

Almost surely, 2^20870147 is an apocalyptic number.

20870147 is a deficient number, since it is larger than the sum of its proper divisors (116773).

20870147 is a wasteful number, since it uses less digits than its factorization.

20870147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116772.

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 20870147 is about 4568.3856010630. The cubic root of 20870147 is about 275.3225834352.

Adding to 20870147 its reverse (74107802), we get a palindrome (94977949).

The spelling of 20870147 in words is "twenty million, eight hundred seventy thousand, one hundred forty-seven".