20423479 has 2 divisors, whose sum is σ = 20423480. Its totient is φ = 20423478.

The previous prime is 20423449. The next prime is 20423483. The reversal of 20423479 is 97432402.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20423479 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20423479.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20423449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10211739 + 10211740.

It is an arithmetic number, because the mean of its divisors is an integer number (10211740).

Almost surely, 2^20423479 is an apocalyptic number.

20423479 is a deficient number, since it is larger than the sum of its proper divisors (1).

20423479 is an equidigital number, since it uses as much as digits as its factorization.

20423479 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 31.

The square root of 20423479 is about 4519.2343378055. The cubic root of 20423479 is about 273.3442280343.

It can be divided in two parts, 20423 and 479, that added together give a palindrome (20902).

The spelling of 20423479 in words is "twenty million, four hundred twenty-three thousand, four hundred seventy-nine".