1211021400 has 48 divisors (see below), whose sum is σ = 3754168200. Its totient is φ = 322938880.

The previous prime is 1211021389. The next prime is 1211021419. The reversal of 1211021400 is 41201121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 1008585 + ... + 1009784.

Almost surely, 2^1211021400 is an apocalyptic number.

1211021400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211021400 is an abundant number, since it is smaller than the sum of its proper divisors (2543146800).

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

1211021400 is a wasteful number, since it uses less digits than its factorization.

1211021400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2018388 (or 2018379 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1211021400 is about 34799.7327575946. The cubic root of 1211021400 is about 1065.9019888369.

Adding to 1211021400 its reverse (41201121), we get a palindrome (1252222521).

The spelling of 1211021400 in words is "one billion, two hundred eleven million, twenty-one thousand, four hundred".