20309679 has 24 divisors (see below), whose sum is σ = 33454512. Its totient is φ = 11761920.

The previous prime is 20309591. The next prime is 20309683. The reversal of 20309679 is 97690302.

It is not a de Polignac number, because 20309679 - 2⁷ = 20309551 is a prime.

It is a super-2 number, since 2×20309679² = 824966122166082, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20309699) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3117 + ... + 7094.

It is an arithmetic number, because the mean of its divisors is an integer number (1393938).

Almost surely, 2^20309679 is an apocalyptic number.

20309679 is a deficient number, since it is larger than the sum of its proper divisors (13144833).

20309679 is a wasteful number, since it uses less digits than its factorization.

20309679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10247 (or 10244 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 36.

The square root of 20309679 is about 4506.6261216125. The cubic root of 20309679 is about 272.8355891269.

The spelling of 20309679 in words is "twenty million, three hundred nine thousand, six hundred seventy-nine".