20528240 has 20 divisors (see below), whose sum is σ = 47728344. Its totient is φ = 8211264.

The previous prime is 20528203. The next prime is 20528251. The reversal of 20528240 is 4282502.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128222 + ... + 128381.

Almost surely, 2^20528240 is an apocalyptic number.

20528240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20528240 is an abundant number, since it is smaller than the sum of its proper divisors (27200104).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20528240 is a wasteful number, since it uses less digits than its factorization.

20528240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256616 (or 256610 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 20528240 is about 4530.8100820935. The cubic root of 20528240 is about 273.8107987530.

The spelling of 20528240 in words is "twenty million, five hundred twenty-eight thousand, two hundred forty".