1978925688 has 32 divisors (see below), whose sum is σ = 5497016400. Its totient is φ = 659641824.

The previous prime is 1978925657. The next prime is 1978925701. The reversal of 1978925688 is 8865298791.

It is a happy number.

It is a super-2 number, since 2×1978925688² = 7832293757252546688, which contains 22 as substring.

It is a congruent number.

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, 4580631 + ... + 4581062.

Almost surely, 2^1978925688 is an apocalyptic number.

1978925688 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1978925688 is an abundant number, since it is smaller than the sum of its proper divisors (3518090712).

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

1978925688 is a wasteful number, since it uses less digits than its factorization.

1978925688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9161708 (or 9161698 counting only the distinct ones).

The product of its digits is 17418240, while the sum is 63.

The square root of 1978925688 is about 44485.1176012832. The cubic root of 1978925688 is about 1255.4800865849.

The spelling of 1978925688 in words is "one billion, nine hundred seventy-eight million, nine hundred twenty-five thousand, six hundred eighty-eight".