10221820 has 24 divisors (see below), whose sum is σ = 24532704. Its totient is φ = 3504576.

The previous prime is 10221803. The next prime is 10221853. The reversal of 10221820 is 2812201.

It is a super-2 number, since 2×10221820² = 208971208224800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 10221794 and 10221803.

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, 36367 + ... + 36646.

It is an arithmetic number, because the mean of its divisors is an integer number (1022196).

Almost surely, 2^10221820 is an apocalyptic number.

10221820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

10221820 is an abundant number, since it is smaller than the sum of its proper divisors (14310884).

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

10221820 is a wasteful number, since it uses less digits than its factorization.

10221820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73029 (or 73027 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 10221820 is about 3197.1581130748. The cubic root of 10221820 is about 217.0248224912.

The spelling of 10221820 in words is "ten million, two hundred twenty-one thousand, eight hundred twenty".