1211021056 has 72 divisors (see below), whose sum is σ = 2769570944. Its totient is φ = 517708800.

The previous prime is 1211020999. The next prime is 1211021087. The reversal of 1211021056 is 6501201121.

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, 1151731 + ... + 1152781.

Almost surely, 2^1211021056 is an apocalyptic number.

1211021056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211021056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1384785472).

1211021056 is an abundant number, since it is smaller than the sum of its proper divisors (1558549888).

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

1211021056 is an equidigital number, since it uses as much as digits as its factorization.

1211021056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1717 (or 1703 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 19.

The square root of 1211021056 is about 34799.7278150275. The cubic root of 1211021056 is about 1065.9018879110.

Adding to 1211021056 its reverse (6501201121), we get a palindrome (7712222177).

The spelling of 1211021056 in words is "one billion, two hundred eleven million, twenty-one thousand, fifty-six".