1206401220 has 72 divisors (see below), whose sum is σ = 3748694040. Its totient is φ = 313858560.

The previous prime is 1206401167. The next prime is 1206401227. The reversal of 1206401220 is 221046021.

1206401220 is a `hidden beast` number, since 1 + 2 + 0 + 640 + 1 + 2 + 20 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 367236 + 1206033984 = 606^2 + 34728^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 1206401193 and 1206401202.

It is not an unprimeable number, because it can be changed into a prime (1206401227) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74355 + ... + 89114.

It is an arithmetic number, because the mean of its divisors is an integer number (52065195).

Almost surely, 2^1206401220 is an apocalyptic number.

1206401220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1206401220 is an abundant number, since it is smaller than the sum of its proper divisors (2542292820).

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

1206401220 is a wasteful number, since it uses less digits than its factorization.

1206401220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163525 (or 163520 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 1206401220 is about 34733.2869161558. The cubic root of 1206401220 is about 1064.5447502107.

Adding to 1206401220 its reverse (221046021), we get a palindrome (1427447241).

The spelling of 1206401220 in words is "one billion, two hundred six million, four hundred one thousand, two hundred twenty".