15678399820 has 12 divisors (see below), whose sum is σ = 32924639664. Its totient is φ = 6271359920.

The previous prime is 15678399797. The next prime is 15678399839. The reversal of 15678399820 is 2899387651.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 391959976 + ... + 391960015.

It is an arithmetic number, because the mean of its divisors is an integer number (2743719972).

Almost surely, 2^15678399820 is an apocalyptic number.

15678399820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15678399820 is an abundant number, since it is smaller than the sum of its proper divisors (17246239844).

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

15678399820 is a wasteful number, since it uses less digits than its factorization.

15678399820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783920000 (or 783919998 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 58.

The spelling of 15678399820 in words is "fifteen billion, six hundred seventy-eight million, three hundred ninety-nine thousand, eight hundred twenty".