19978231 has 24 divisors (see below), whose sum is σ = 25408320. Its totient is φ = 15567552.

The previous prime is 19978223. The next prime is 19978241. The reversal of 19978231 is 13287991.

It is not a de Polignac number, because 19978231 - 2³ = 19978223 is a prime.

It is a super-2 number, since 2×19978231² = 798259427778722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19978241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50125 + ... + 50521.

It is an arithmetic number, because the mean of its divisors is an integer number (1058680).

Almost surely, 2^19978231 is an apocalyptic number.

19978231 is a deficient number, since it is larger than the sum of its proper divisors (5430089).

19978231 is a wasteful number, since it uses less digits than its factorization.

19978231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503 (or 496 counting only the distinct ones).

The product of its digits is 27216, while the sum is 40.

The square root of 19978231 is about 4469.7014441683. The cubic root of 19978231 is about 271.3432423112.

The spelling of 19978231 in words is "nineteen million, nine hundred seventy-eight thousand, two hundred thirty-one".