1211021552 has 80 divisors (see below), whose sum is σ = 2599416960. Its totient is φ = 546294528.

The previous prime is 1211021533. The next prime is 1211021561. The reversal of 1211021552 is 2551201121.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1651778 + ... + 1652510.

It is an arithmetic number, because the mean of its divisors is an integer number (32492712).

Almost surely, 2^1211021552 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211021552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1299708480).

1211021552 is an abundant number, since it is smaller than the sum of its proper divisors (1388395408).

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

1211021552 is an equidigital number, since it uses as much as digits as its factorization.

1211021552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 827 (or 795 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 20.

The square root of 1211021552 is about 34799.7349415193. The cubic root of 1211021552 is about 1065.9020334321.

Adding to 1211021552 its reverse (2551201121), we get a palindrome (3762222673).

The spelling of 1211021552 in words is "one billion, two hundred eleven million, twenty-one thousand, five hundred fifty-two".