1243400015 has 16 divisors (see below), whose sum is σ = 1752934176. Its totient is φ = 834729600.

The previous prime is 1243399979. The next prime is 1243400017. The reversal of 1243400015 is 5100043421.

It is not a de Polignac number, because 1243400015 - 2¹⁰ = 1243398991 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1243400015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243400017) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 868796 + ... + 870225.

It is an arithmetic number, because the mean of its divisors is an integer number (109558386).

Almost surely, 2^1243400015 is an apocalyptic number.

1243400015 is a deficient number, since it is larger than the sum of its proper divisors (509534161).

1243400015 is a wasteful number, since it uses less digits than its factorization.

1243400015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1739050.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 1243400015 is about 35261.8776442775. The cubic root of 1243400015 is about 1075.3181002019.

Adding to 1243400015 its reverse (5100043421), we get a palindrome (6343443436).

The spelling of 1243400015 in words is "one billion, two hundred forty-three million, four hundred thousand, fifteen".