1285720272 has 90 divisors (see below), whose sum is σ = 3797732562. Its totient is φ = 406000512.

The previous prime is 1285720243. The next prime is 1285720279. The reversal of 1285720272 is 2720275821.

1285720272 is a `hidden beast` number, since 12 + 8 + 572 + 0 + 2 + 72 = 666.

It can be written as a sum of positive squares in only one way, i.e., 786465936 + 499254336 = 28044^2 + 22344^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1285720279) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 39618 + ... + 64350.

Almost surely, 2^1285720272 is an apocalyptic number.

1285720272 is a gapful number since it is divisible by the number (12) 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 1285720272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1898866281).

1285720272 is an abundant number, since it is smaller than the sum of its proper divisors (2512012290).

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

1285720272 is a wasteful number, since it uses less digits than its factorization.

1285720272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24785 (or 24757 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 36.

The square root of 1285720272 is about 35856.9417547007. The cubic root of 1285720272 is about 1087.3820606146.

The spelling of 1285720272 in words is "one billion, two hundred eighty-five million, seven hundred twenty thousand, two hundred seventy-two".