19681431 has 16 divisors (see below), whose sum is σ = 32717568. Its totient is φ = 10224000.

The previous prime is 19681429. The next prime is 19681433. The reversal of 19681431 is 13418691.

It is an interprime number because it is at equal distance from previous prime (19681429) and next prime (19681433).

It is not a de Polignac number, because 19681431 - 2¹ = 19681429 is a prime.

It is a super-2 number, since 2×19681431² = 774717452415522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 19681392 and 19681401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19681433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42370 + ... + 42831.

It is an arithmetic number, because the mean of its divisors is an integer number (2044848).

Almost surely, 2^19681431 is an apocalyptic number.

19681431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19681431 is a deficient number, since it is larger than the sum of its proper divisors (13036137).

19681431 is a wasteful number, since it uses less digits than its factorization.

19681431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85222.

The product of its digits is 5184, while the sum is 33.

The square root of 19681431 is about 4436.3758857879. The cubic root of 19681431 is about 269.9928255981.

The spelling of 19681431 in words is "nineteen million, six hundred eighty-one thousand, four hundred thirty-one".