1205511420 has 96 divisors (see below), whose sum is σ = 3530838528. Its totient is φ = 306738432.

The previous prime is 1205511409. The next prime is 1205511431. The reversal of 1205511420 is 241155021.

It is an interprime number because it is at equal distance from previous prime (1205511409) and next prime (1205511431).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 754062 + ... + 755658.

It is an arithmetic number, because the mean of its divisors is an integer number (36779568).

Almost surely, 2^1205511420 is an apocalyptic number.

1205511420 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 1205511420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1765419264).

1205511420 is an abundant number, since it is smaller than the sum of its proper divisors (2325327108).

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

1205511420 is a wasteful number, since it uses less digits than its factorization.

1205511420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2179 (or 2177 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 1205511420 is about 34720.4755151769. The cubic root of 1205511420 is about 1064.2829619873.

Adding to 1205511420 its reverse (241155021), we get a palindrome (1446666441).

The spelling of 1205511420 in words is "one billion, two hundred five million, five hundred eleven thousand, four hundred twenty".