1243209978 has 16 divisors (see below), whose sum is σ = 2762688960. Its totient is φ = 414403308.

The previous prime is 1243209977. The next prime is 1243210013. The reversal of 1243209978 is 8799023421.

It is not an unprimeable number, because it can be changed into a prime (1243209971) 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, 11511150 + ... + 11511257.

It is an arithmetic number, because the mean of its divisors is an integer number (172668060).

Almost surely, 2^1243209978 is an apocalyptic number.

1243209978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1243209978 is an abundant number, since it is smaller than the sum of its proper divisors (1519478982).

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

1243209978 is a wasteful number, since it uses less digits than its factorization.

1243209978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23022418 (or 23022412 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 1243209978 is about 35259.1828890007. The cubic root of 1243209978 is about 1075.2633147654.

The spelling of 1243209978 in words is "one billion, two hundred forty-three million, two hundred nine thousand, nine hundred seventy-eight".