20521100 has 18 divisors (see below), whose sum is σ = 44531004. Its totient is φ = 8208400.

The previous prime is 20521099. The next prime is 20521147. The reversal of 20521100 is 112502.

It is a super-2 number, since 2×20521100² = 842231090420000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 102506 + ... + 102705.

Almost surely, 2^20521100 is an apocalyptic number.

20521100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20521100 is an abundant number, since it is smaller than the sum of its proper divisors (24009904).

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

20521100 is a wasteful number, since it uses less digits than its factorization.

20521100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205225 (or 205218 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 11.

The square root of 20521100 is about 4530.0220750014. The cubic root of 20521100 is about 273.7790500367.

Adding to 20521100 its reverse (112502), we get a palindrome (20633602).

The spelling of 20521100 in words is "twenty million, five hundred twenty-one thousand, one hundred".