20354557 has 4 divisors (see below), whose sum is σ = 20375740. Its totient is φ = 20333376.

The previous prime is 20354527. The next prime is 20354561. The reversal of 20354557 is 75545302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15452761 + 4901796 = 3931^2 + 2214^2 .

It is a cyclic number.

It is not a de Polignac number, because 20354557 - 2¹¹ = 20352509 is a prime.

It is a super-4 number, since 4×20354557⁴ (a number of 30 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20354527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9078 + ... + 11095.

It is an arithmetic number, because the mean of its divisors is an integer number (5093935).

Almost surely, 2^20354557 is an apocalyptic number.

It is an amenable number.

20354557 is a deficient number, since it is larger than the sum of its proper divisors (21183).

20354557 is a wasteful number, since it uses less digits than its factorization.

20354557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21182.

The product of its (nonzero) digits is 21000, while the sum is 31.

The square root of 20354557 is about 4511.6024869219. The cubic root of 20354557 is about 273.0364015561.

Adding to 20354557 its reverse (75545302), we get a palindrome (95899859).

The spelling of 20354557 in words is "twenty million, three hundred fifty-four thousand, five hundred fifty-seven".