20415457 has 2 divisors, whose sum is σ = 20415458. Its totient is φ = 20415456.

The previous prime is 20415431. The next prime is 20415463. The reversal of 20415457 is 75451402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12327121 + 8088336 = 3511^2 + 2844^2 .

It is a cyclic number.

It is not a de Polignac number, because 20415457 - 2¹¹ = 20413409 is a prime.

It is not a weakly prime, because it can be changed into another prime (20415257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10207728 + 10207729.

It is an arithmetic number, because the mean of its divisors is an integer number (10207729).

Almost surely, 2^20415457 is an apocalyptic number.

It is an amenable number.

20415457 is a deficient number, since it is larger than the sum of its proper divisors (1).

20415457 is an equidigital number, since it uses as much as digits as its factorization.

20415457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5600, while the sum is 28.

The square root of 20415457 is about 4518.3467109110. The cubic root of 20415457 is about 273.3084350048.

Adding to 20415457 its reverse (75451402), we get a palindrome (95866859).

The spelling of 20415457 in words is "twenty million, four hundred fifteen thousand, four hundred fifty-seven".