20975647 has 8 divisors (see below), whose sum is σ = 26151552. Its totient is φ = 16344600.

The previous prime is 20975627. The next prime is 20975657. The reversal of 20975647 is 74657902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20975647 - 2⁷ = 20975519 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20975627) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136129 + ... + 136282.

It is an arithmetic number, because the mean of its divisors is an integer number (3268944).

Almost surely, 2^20975647 is an apocalyptic number.

20975647 is a deficient number, since it is larger than the sum of its proper divisors (5175905).

20975647 is a wasteful number, since it uses less digits than its factorization.

20975647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272429.

The product of its (nonzero) digits is 105840, while the sum is 40.

The square root of 20975647 is about 4579.9177940221. The cubic root of 20975647 is about 275.7857286395.

It can be divided in two parts, 2097 and 5647, that added together give a square (7744 = 88²).

The spelling of 20975647 in words is "twenty million, nine hundred seventy-five thousand, six hundred forty-seven".