20617279 has 4 divisors (see below), whose sum is σ = 20755800. Its totient is φ = 20478760.

The previous prime is 20617271. The next prime is 20617291. The reversal of 20617279 is 97271602.

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 20617279 - 2³ = 20617271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20617271) 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, 69037 + ... + 69334.

It is an arithmetic number, because the mean of its divisors is an integer number (5188950).

Almost surely, 2^20617279 is an apocalyptic number.

20617279 is a deficient number, since it is larger than the sum of its proper divisors (138521).

20617279 is a wasteful number, since it uses less digits than its factorization.

20617279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138520.

The product of its (nonzero) digits is 10584, while the sum is 34.

The square root of 20617279 is about 4540.6253974535. The cubic root of 20617279 is about 274.2061025898.

The spelling of 20617279 in words is "twenty million, six hundred seventeen thousand, two hundred seventy-nine".