19928431 has 4 divisors (see below), whose sum is σ = 20074032. Its totient is φ = 19782832.

The previous prime is 19928401. The next prime is 19928453. The reversal of 19928431 is 13482991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19928431 - 2¹⁵ = 19895663 is a prime.

It is a super-2 number, since 2×19928431² = 794284724243522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19928401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72595 + ... + 72868.

It is an arithmetic number, because the mean of its divisors is an integer number (5018508).

Almost surely, 2^19928431 is an apocalyptic number.

19928431 is a deficient number, since it is larger than the sum of its proper divisors (145601).

19928431 is a wasteful number, since it uses less digits than its factorization.

19928431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145600.

The product of its digits is 15552, while the sum is 37.

The square root of 19928431 is about 4464.1271263260. The cubic root of 19928431 is about 271.1175944220.

The spelling of 19928431 in words is "nineteen million, nine hundred twenty-eight thousand, four hundred thirty-one".