1211306880 has 128 divisors (see below), whose sum is σ = 4412666880. Its totient is φ = 276867072.

The previous prime is 1211306849. The next prime is 1211306881. The reversal of 1211306880 is 886031121.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211306881) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31624 + ... + 58503.

It is an arithmetic number, because the mean of its divisors is an integer number (34473960).

Almost surely, 2^1211306880 is an apocalyptic number.

1211306880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211306880 is an abundant number, since it is smaller than the sum of its proper divisors (3201360000).

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

1211306880 is an equidigital number, since it uses as much as digits as its factorization.

1211306880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90156 (or 90144 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 1211306880 is about 34803.8342715282. The cubic root of 1211306880 is about 1065.9857390201.

The spelling of 1211306880 in words is "one billion, two hundred eleven million, three hundred six thousand, eight hundred eighty".