1285203640 has 32 divisors (see below), whose sum is σ = 3304810080. Its totient is φ = 440641152.

The previous prime is 1285203629. The next prime is 1285203649. The reversal of 1285203640 is 463025821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1285203649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2294727 + ... + 2295286.

It is an arithmetic number, because the mean of its divisors is an integer number (103275315).

Almost surely, 2^1285203640 is an apocalyptic number.

1285203640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1285203640 is an abundant number, since it is smaller than the sum of its proper divisors (2019606440).

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

1285203640 is a wasteful number, since it uses less digits than its factorization.

1285203640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4590031 (or 4590027 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 1285203640 is about 35849.7369585887. The cubic root of 1285203640 is about 1087.2363960553.

The spelling of 1285203640 in words is "one billion, two hundred eighty-five million, two hundred three thousand, six hundred forty".