19881970 has 8 divisors (see below), whose sum is σ = 35787564. Its totient is φ = 7952784.

The previous prime is 19881947. The next prime is 19881971. The reversal of 19881970 is 7918891.

It can be written as a sum of positive squares in 2 ways, for example, as 18326961 + 1555009 = 4281^2 + 1247^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (19881971) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 994089 + ... + 994108.

Almost surely, 2^19881970 is an apocalyptic number.

19881970 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19881970 is a deficient number, since it is larger than the sum of its proper divisors (15905594).

19881970 is a wasteful number, since it uses less digits than its factorization.

19881970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1988204.

The product of its (nonzero) digits is 36288, while the sum is 43.

The square root of 19881970 is about 4458.9202728912. The cubic root of 19881970 is about 270.9067366062.

The spelling of 19881970 in words is "nineteen million, eight hundred eighty-one thousand, nine hundred seventy".