19719445 has 8 divisors (see below), whose sum is σ = 24110136. Its totient is φ = 15477696.

The previous prime is 19719443. The next prime is 19719481. The reversal of 19719445 is 54491791.

It can be written as a sum of positive squares in 4 ways, for example, as 3663396 + 16056049 = 1914^2 + 4007^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19719445 - 2¹ = 19719443 is a prime.

It is a super-2 number, since 2×19719445² = 777713022216050, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19719398 and 19719407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19719443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36942 + ... + 37471.

It is an arithmetic number, because the mean of its divisors is an integer number (3013767).

Almost surely, 2^19719445 is an apocalyptic number.

It is an amenable number.

19719445 is a deficient number, since it is larger than the sum of its proper divisors (4390691).

19719445 is an equidigital number, since it uses as much as digits as its factorization.

19719445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74471.

The product of its digits is 45360, while the sum is 40.

The square root of 19719445 is about 4440.6581719380. The cubic root of 19719445 is about 270.1665410575.

It can be divided in two parts, 19719 and 445, that added together give a square (20164 = 142²).

The spelling of 19719445 in words is "nineteen million, seven hundred nineteen thousand, four hundred forty-five".