20647379 has 4 divisors (see below), whose sum is σ = 20771184. Its totient is φ = 20523576.

The previous prime is 20647351. The next prime is 20647387. The reversal of 20647379 is 97374602.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20647379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20647309) 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, 61652 + ... + 61985.

It is an arithmetic number, because the mean of its divisors is an integer number (5192796).

Almost surely, 2^20647379 is an apocalyptic number.

20647379 is a deficient number, since it is larger than the sum of its proper divisors (123805).

20647379 is a wasteful number, since it uses less digits than its factorization.

20647379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123804.

The product of its (nonzero) digits is 63504, while the sum is 38.

The square root of 20647379 is about 4543.9387099740. The cubic root of 20647379 is about 274.3394792323.

The spelling of 20647379 in words is "twenty million, six hundred forty-seven thousand, three hundred seventy-nine".