19997505 has 48 divisors (see below), whose sum is σ = 38413440. Its totient is φ = 9542400.

The previous prime is 19997489. The next prime is 19997521. The reversal of 19997505 is 50579991.

It is an interprime number because it is at equal distance from previous prime (19997489) and next prime (19997521).

It is not a de Polignac number, because 19997505 - 2⁴ = 19997489 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 34861 + ... + 35429.

It is an arithmetic number, because the mean of its divisors is an integer number (800280).

Almost surely, 2^19997505 is an apocalyptic number.

19997505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19997505 is a deficient number, since it is larger than the sum of its proper divisors (18415935).

19997505 is a wasteful number, since it uses less digits than its factorization.

19997505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 662 (or 659 counting only the distinct ones).

The product of its (nonzero) digits is 127575, while the sum is 45.

The square root of 19997505 is about 4471.8569968191. The cubic root of 19997505 is about 271.4304737368.

It can be divided in two parts, 19997 and 505, that added together give a palindrome (20502).

The spelling of 19997505 in words is "nineteen million, nine hundred ninety-seven thousand, five hundred five".