1285557220 has 12 divisors (see below), whose sum is σ = 2699670204. Its totient is φ = 514222880.

The previous prime is 1285557191. The next prime is 1285557253. The reversal of 1285557220 is 227555821.

It can be written as a sum of positive squares in 2 ways, for example, as 1003115584 + 282441636 = 31672^2 + 16806^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1285557220.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32138911 + ... + 32138950.

It is an arithmetic number, because the mean of its divisors is an integer number (224972517).

Almost surely, 2^1285557220 is an apocalyptic number.

1285557220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1285557220 is an abundant number, since it is smaller than the sum of its proper divisors (1414112984).

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

1285557220 is a wasteful number, since it uses less digits than its factorization.

1285557220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64277870 (or 64277868 counting only the distinct ones).

The product of its (nonzero) digits is 56000, while the sum is 37.

The square root of 1285557220 is about 35854.6680363938. The cubic root of 1285557220 is about 1087.3360922654.

The spelling of 1285557220 in words is "one billion, two hundred eighty-five million, five hundred fifty-seven thousand, two hundred twenty".