20420479 has 2 divisors, whose sum is σ = 20420480. Its totient is φ = 20420478.

The previous prime is 20420453. The next prime is 20420503. The reversal of 20420479 is 97402402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20420479 - 2¹⁵ = 20387711 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20420579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10210239 + 10210240.

It is an arithmetic number, because the mean of its divisors is an integer number (10210240).

Almost surely, 2^20420479 is an apocalyptic number.

20420479 is a deficient number, since it is larger than the sum of its proper divisors (1).

20420479 is an equidigital number, since it uses as much as digits as its factorization.

20420479 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 20420479 is about 4518.9024109843. The cubic root of 20420479 is about 273.3308435559.

The spelling of 20420479 in words is "twenty million, four hundred twenty thousand, four hundred seventy-nine".