1243640540 has 48 divisors (see below), whose sum is σ = 2644125120. Its totient is φ = 491297280.

The previous prime is 1243640513. The next prime is 1243640549. The reversal of 1243640540 is 450463421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243640549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1171610 + ... + 1172670.

It is an arithmetic number, because the mean of its divisors is an integer number (55085940).

Almost surely, 2^1243640540 is an apocalyptic number.

1243640540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1243640540 is an abundant number, since it is smaller than the sum of its proper divisors (1400484580).

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

1243640540 is a wasteful number, since it uses less digits than its factorization.

1243640540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1742 (or 1740 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 1243640540 is about 35265.2880322847. The cubic root of 1243640540 is about 1075.3874327330.

The spelling of 1243640540 in words is "one billion, two hundred forty-three million, six hundred forty thousand, five hundred forty".