1243539740 has 24 divisors (see below), whose sum is σ = 2748878160. Its totient is φ = 471235968.

The previous prime is 1243539727. The next prime is 1243539757. The reversal of 1243539740 is 479353421.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 1243539694 and 1243539703.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1635857 + ... + 1636616.

It is an arithmetic number, because the mean of its divisors is an integer number (114536590).

Almost surely, 2^1243539740 is an apocalyptic number.

1243539740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1243539740 is an abundant number, since it is smaller than the sum of its proper divisors (1505338420).

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

1243539740 is a wasteful number, since it uses less digits than its factorization.

1243539740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3272501 (or 3272499 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 38.

The square root of 1243539740 is about 35263.8588359244. The cubic root of 1243539740 is about 1075.3583777184.

The spelling of 1243539740 in words is "one billion, two hundred forty-three million, five hundred thirty-nine thousand, seven hundred forty".