1211000020 has 24 divisors (see below), whose sum is σ = 2544796800. Its totient is φ = 484076832.

The previous prime is 1210999987. The next prime is 1211000023. The reversal of 1211000020 is 200001121.

It is a junction number, because it is equal to n+sod(n) for n = 1210999967 and 1211000012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211000023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11761 + ... + 50599.

It is an arithmetic number, because the mean of its divisors is an integer number (106033200).

Almost surely, 2^1211000020 is an apocalyptic number.

1211000020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211000020 is an abundant number, since it is smaller than the sum of its proper divisors (1333796780).

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

1211000020 is a wasteful number, since it uses less digits than its factorization.

1211000020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40407 (or 40405 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 1211000020 is about 34799.4255699717. The cubic root of 1211000020 is about 1065.8957161378.

Adding to 1211000020 its reverse (200001121), we get a palindrome (1411001141).

The spelling of 1211000020 in words is "one billion, two hundred eleven million, twenty", and thus it is an aban number.