1216271400 has 96 divisors (see below), whose sum is σ = 3872415840. Its totient is φ = 315567360.

The previous prime is 1216271387. The next prime is 1216271411. The reversal of 1216271400 is 41726121.

It is a super-2 number, since 2×1216271400² = 2958632236915920000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5194 + ... + 49593.

It is an arithmetic number, because the mean of its divisors is an integer number (40337665).

Almost surely, 2^1216271400 is an apocalyptic number.

1216271400 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 1216271400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1936207920).

1216271400 is an abundant number, since it is smaller than the sum of its proper divisors (2656144440).

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

1216271400 is a wasteful number, since it uses less digits than its factorization.

1216271400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54843 (or 54834 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 1216271400 is about 34875.0827956006. The cubic root of 1216271400 is about 1067.4400619379.

Adding to 1216271400 its reverse (41726121), we get a palindrome (1257997521).

The spelling of 1216271400 in words is "one billion, two hundred sixteen million, two hundred seventy-one thousand, four hundred".