1217942478 has 24 divisors (see below), whose sum is σ = 2639547768. Its totient is φ = 405877392.

The previous prime is 1217942471. The next prime is 1217942497. The reversal of 1217942478 is 8742497121.

1217942478 is a `hidden beast` number, since 1 + 2 + 179 + 4 + 2 + 478 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1217942471) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 103176 + ... + 114372.

It is an arithmetic number, because the mean of its divisors is an integer number (109981157).

Almost surely, 2^1217942478 is an apocalyptic number.

1217942478 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1217942478 is an abundant number, since it is smaller than the sum of its proper divisors (1421605290).

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

1217942478 is a wasteful number, since it uses less digits than its factorization.

1217942478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17248 (or 17245 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 1217942478 is about 34899.0326226960. The cubic root of 1217942478 is about 1067.9287026848.

The spelling of 1217942478 in words is "one billion, two hundred seventeen million, nine hundred forty-two thousand, four hundred seventy-eight".