19800045 has 20 divisors (see below), whose sum is σ = 35494140. Its totient is φ = 10559808.

The previous prime is 19799993. The next prime is 19800083. The reversal of 19800045 is 54000891.

It can be written as a sum of positive squares in 2 ways, for example, as 9418761 + 10381284 = 3069^2 + 3222^2 .

It is not a de Polignac number, because 19800045 - 2⁶ = 19799981 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 19799991 and 19800018.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 24040 + ... + 24849.

It is an arithmetic number, because the mean of its divisors is an integer number (1774707).

Almost surely, 2^19800045 is an apocalyptic number.

19800045 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19800045 is a deficient number, since it is larger than the sum of its proper divisors (15694095).

19800045 is an equidigital number, since it uses as much as digits as its factorization.

19800045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48906 (or 48897 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 19800045 is about 4449.7241487535. The cubic root of 19800045 is about 270.5341278493.

The spelling of 19800045 in words is "nineteen million, eight hundred thousand, forty-five".