19781253 has 20 divisors (see below), whose sum is σ = 29849248. Its totient is φ = 13053960.

The previous prime is 19781231. The next prime is 19781269. The reversal of 19781253 is 35218791.

It is not a de Polignac number, because 19781253 - 2⁵ = 19781221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19781213) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 7158 + ... + 9528.

Almost surely, 2^19781253 is an apocalyptic number.

It is an amenable number.

19781253 is a deficient number, since it is larger than the sum of its proper divisors (10067995).

19781253 is a wasteful number, since it uses less digits than its factorization.

19781253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2486 (or 2477 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 19781253 is about 4447.6120559239. The cubic root of 19781253 is about 270.4485137926.

The spelling of 19781253 in words is "nineteen million, seven hundred eighty-one thousand, two hundred fifty-three".