20420345 has 16 divisors (see below), whose sum is σ = 28140480. Its totient is φ = 14068800.

The previous prime is 20420329. The next prime is 20420347. The reversal of 20420345 is 54302402.

It is not a de Polignac number, because 20420345 - 2⁴ = 20420329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20420347) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8726 + ... + 10815.

It is an arithmetic number, because the mean of its divisors is an integer number (1758780).

Almost surely, 2^20420345 is an apocalyptic number.

It is an amenable number.

20420345 is a deficient number, since it is larger than the sum of its proper divisors (7720135).

20420345 is a wasteful number, since it uses less digits than its factorization.

20420345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19576.

The product of its (nonzero) digits is 960, while the sum is 20.

The square root of 20420345 is about 4518.8875843508. The cubic root of 20420345 is about 273.3302456853.

Adding to 20420345 its reverse (54302402), we get a palindrome (74722747).

The spelling of 20420345 in words is "twenty million, four hundred twenty thousand, three hundred forty-five".