1231889978 has 16 divisors (see below), whose sum is σ = 2017612800. Its totient is φ = 559452000.

The previous prime is 1231889963. The next prime is 1231889999. The reversal of 1231889978 is 8799881321.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 998 + ... + 49646.

It is an arithmetic number, because the mean of its divisors is an integer number (126100800).

Almost surely, 2^1231889978 is an apocalyptic number.

1231889978 is a deficient number, since it is larger than the sum of its proper divisors (785722822).

1231889978 is a wasteful number, since it uses less digits than its factorization.

1231889978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49813.

The product of its digits is 1741824, while the sum is 56.

The square root of 1231889978 is about 35098.2902432583. The cubic root of 1231889978 is about 1071.9897694548.

The spelling of 1231889978 in words is "one billion, two hundred thirty-one million, eight hundred eighty-nine thousand, nine hundred seventy-eight".