1211306400 has 504 divisors, whose sum is σ = 4644952704. Its totient is φ = 307929600.

The previous prime is 1211306387. The next prime is 1211306401. The reversal of 1211306400 is 46031121.

It is a happy number.

1211306400 is a `hidden beast` number, since 1 + 21 + 1 + 3 + 0 + 640 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211306401) by changing a digit.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 18079167 + ... + 18079233.

It is an arithmetic number, because the mean of its divisors is an integer number (9216176).

Almost surely, 2^1211306400 is an apocalyptic number.

1211306400 is a gapful number since it is divisible by the number (10) 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 1211306400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2322476352).

1211306400 is an abundant number, since it is smaller than the sum of its proper divisors (3433646304).

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

1211306400 is an equidigital number, since it uses as much as digits as its factorization.

1211306400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 1211306400 is about 34803.8273757356. The cubic root of 1211306400 is about 1065.9855982153.

Adding to 1211306400 its reverse (46031121), we get a palindrome (1257337521).

The spelling of 1211306400 in words is "one billion, two hundred eleven million, three hundred six thousand, four hundred".