221210020 has 12 divisors (see below), whose sum is σ = 464541084. Its totient is φ = 88484000.

The previous prime is 221210009. The next prime is 221210051. The reversal of 221210020 is 20012122.

It can be written as a sum of positive squares in 2 ways, for example, as 28111204 + 193098816 = 5302^2 + 13896^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 221209979 and 221210006.

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, 5530231 + ... + 5530270.

It is an arithmetic number, because the mean of its divisors is an integer number (38711757).

Almost surely, 2^221210020 is an apocalyptic number.

221210020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221210020 is an abundant number, since it is smaller than the sum of its proper divisors (243331064).

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

221210020 is a wasteful number, since it uses less digits than its factorization.

221210020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11060510 (or 11060508 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 221210020 is about 14873.1308069283. The cubic root of 221210020 is about 604.7858176795.

Adding to 221210020 its reverse (20012122), we get a palindrome (241222142).

The spelling of 221210020 in words is "two hundred twenty-one million, two hundred ten thousand, twenty".