39991563 has 20 divisors (see below), whose sum is σ = 60640360. Its totient is φ = 26259552.

The previous prime is 39991547. The next prime is 39991573. The reversal of 39991563 is 36519993.

It is not a de Polignac number, because 39991563 - 2⁴ = 39991547 is a prime.

It is a super-2 number, since 2×39991563² = 3198650222365938, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (39991573) 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 19 ways as a sum of consecutive naturals, for example, 1743 + ... + 9111.

It is an arithmetic number, because the mean of its divisors is an integer number (3032018).

Almost surely, 2^39991563 is an apocalyptic number.

39991563 is a deficient number, since it is larger than the sum of its proper divisors (20648797).

39991563 is an equidigital number, since it uses as much as digits as its factorization.

39991563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7448 (or 7439 counting only the distinct ones).

The product of its digits is 196830, while the sum is 45.

The square root of 39991563 is about 6323.8882817457. Note that the first 3 decimals coincide. The cubic root of 39991563 is about 341.9711425328.

The spelling of 39991563 in words is "thirty-nine million, nine hundred ninety-one thousand, five hundred sixty-three".