1978289390 has 128 divisors (see below), whose sum is σ = 4584729600. Its totient is φ = 596736000.

The previous prime is 1978289389. The next prime is 1978289429. The reversal of 1978289390 is 939828791.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4933190 + ... + 4933590.

It is an arithmetic number, because the mean of its divisors is an integer number (35818200).

Almost surely, 2^1978289390 is an apocalyptic number.

1978289390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1978289390 is an abundant number, since it is smaller than the sum of its proper divisors (2606440210).

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

1978289390 is a wasteful number, since it uses less digits than its factorization.

1978289390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 618.

The product of its (nonzero) digits is 1959552, while the sum is 56.

The square root of 1978289390 is about 44477.9652187462. The cubic root of 1978289390 is about 1255.3455110239.

The spelling of 1978289390 in words is "one billion, nine hundred seventy-eight million, two hundred eighty-nine thousand, three hundred ninety".