211220020 has 36 divisors (see below), whose sum is σ = 487557252. Its totient is φ = 76806400.

The previous prime is 211220011. The next prime is 211220027. The reversal of 211220020 is 20022112.

It can be written as a sum of positive squares in 2 ways, for example, as 159466384 + 51753636 = 12628^2 + 7194^2 .

It is a super-2 number, since 2×211220020² = 89227793697600800, which contains 22 as substring.

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 = 211219979 and 211220006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211220027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41221 + ... + 46060.

It is an arithmetic number, because the mean of its divisors is an integer number (13543257).

Almost surely, 2^211220020 is an apocalyptic number.

211220020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211220020 is an abundant number, since it is smaller than the sum of its proper divisors (276337232).

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

211220020 is a wasteful number, since it uses less digits than its factorization.

211220020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87312 (or 87299 counting only the distinct ones).

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

The square root of 211220020 is about 14533.4104738014. The cubic root of 211220020 is about 595.5410374350.

Adding to 211220020 its reverse (20022112), we get a palindrome (231242132).

The spelling of 211220020 in words is "two hundred eleven million, two hundred twenty thousand, twenty".