20513285 has 8 divisors (see below), whose sum is σ = 26509560. Its totient is φ = 15148224.

The previous prime is 20513267. The next prime is 20513299. The reversal of 20513285 is 58231502.

It can be written as a sum of positive squares in 4 ways, for example, as 3157729 + 17355556 = 1777^2 + 4166^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20513285 - 2⁸ = 20513029 is a prime.

It is a super-2 number, since 2×20513285² = 841589722982450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 157730 + ... + 157859.

It is an arithmetic number, because the mean of its divisors is an integer number (3313695).

Almost surely, 2^20513285 is an apocalyptic number.

It is an amenable number.

20513285 is a deficient number, since it is larger than the sum of its proper divisors (5996275).

20513285 is a wasteful number, since it uses less digits than its factorization.

20513285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315607.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 20513285 is about 4529.1594142843. The cubic root of 20513285 is about 273.7442914234.

Adding to 20513285 its reverse (58231502), we get a palindrome (78744787).

The spelling of 20513285 in words is "twenty million, five hundred thirteen thousand, two hundred eighty-five".