19781925 has 12 divisors (see below), whose sum is σ = 32706240. Its totient is φ = 10550320.

The previous prime is 19781891. The next prime is 19781953. The reversal of 19781925 is 52918791.

It is not a de Polignac number, because 19781925 - 2¹⁴ = 19765541 is a prime.

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 (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 131805 + ... + 131954.

It is an arithmetic number, because the mean of its divisors is an integer number (2725520).

Almost surely, 2^19781925 is an apocalyptic number.

19781925 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19781925 is a deficient number, since it is larger than the sum of its proper divisors (12924315).

19781925 is a wasteful number, since it uses less digits than its factorization.

19781925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263772 (or 263767 counting only the distinct ones).

The product of its digits is 45360, while the sum is 42.

The square root of 19781925 is about 4447.6876014397. The cubic root of 19781925 is about 270.4515762771.

It can be divided in two parts, 19781 and 925, that added together give a triangular number (20706 = T₂₀₃).

The spelling of 19781925 in words is "nineteen million, seven hundred eighty-one thousand, nine hundred twenty-five".