20361557 has 2 divisors, whose sum is σ = 20361558. Its totient is φ = 20361556.

The previous prime is 20361553. The next prime is 20361569. The reversal of 20361557 is 75516302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12666481 + 7695076 = 3559^2 + 2774^2 .

It is a cyclic number.

It is not a de Polignac number, because 20361557 - 2² = 20361553 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20361553) 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, 10180778 + 10180779.

It is an arithmetic number, because the mean of its divisors is an integer number (10180779).

Almost surely, 2^20361557 is an apocalyptic number.

It is an amenable number.

20361557 is a deficient number, since it is larger than the sum of its proper divisors (1).

20361557 is an equidigital number, since it uses as much as digits as its factorization.

20361557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6300, while the sum is 29.

The square root of 20361557 is about 4512.3781978021. The cubic root of 20361557 is about 273.0676973450.

Adding to 20361557 its reverse (75516302), we get a palindrome (95877859).

The spelling of 20361557 in words is "twenty million, three hundred sixty-one thousand, five hundred fifty-seven".