1213640442 has 128 divisors (see below), whose sum is σ = 3158507520. Its totient is φ = 338299200.

The previous prime is 1213640431. The next prime is 1213640497. The reversal of 1213640442 is 2440463121.

It is a happy number.

1213640442 is a `hidden beast` number, since 1 + 2 + 13 + 640 + 4 + 4 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3168583 + ... + 3168965.

It is an arithmetic number, because the mean of its divisors is an integer number (24675840).

Almost surely, 2^1213640442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1213640442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1579253760).

1213640442 is an abundant number, since it is smaller than the sum of its proper divisors (1944867078).

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

1213640442 is a wasteful number, since it uses less digits than its factorization.

1213640442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 585 (or 579 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 1213640442 is about 34837.3426368889. The cubic root of 1213640442 is about 1066.6698343439.

The spelling of 1213640442 in words is "one billion, two hundred thirteen million, six hundred forty thousand, four hundred forty-two".