18931969 has 4 divisors (see below), whose sum is σ = 21636544. Its totient is φ = 16227396.

The previous prime is 18931963. The next prime is 18931981. The reversal of 18931969 is 96913981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 96913981 = 8597 ⋅11273.

It is a cyclic number.

It is not a de Polignac number, because 18931969 - 2¹³ = 18923777 is a prime.

It is a super-2 number, since 2×18931969² = 716838900433922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18931963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1352277 + ... + 1352290.

It is an arithmetic number, because the mean of its divisors is an integer number (5409136).

Almost surely, 2^18931969 is an apocalyptic number.

It is an amenable number.

18931969 is a deficient number, since it is larger than the sum of its proper divisors (2704575).

18931969 is an equidigital number, since it uses as much as digits as its factorization.

18931969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2704574.

The product of its digits is 104976, while the sum is 46.

The square root of 18931969 is about 4351.0882546784. The cubic root of 18931969 is about 266.5213032402.

It can be divided in two parts, 18931 and 969, that added together give a triangular number (19900 = T₁₉₉).

The spelling of 18931969 in words is "eighteen million, nine hundred thirty-one thousand, nine hundred sixty-nine".