39887561 has 4 divisors (see below), whose sum is σ = 45585792. Its totient is φ = 34189332.

The previous prime is 39887539. The next prime is 39887563. The reversal of 39887561 is 16578893.

It is a happy number.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39887561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (39887563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2849105 + ... + 2849118.

It is an arithmetic number, because the mean of its divisors is an integer number (11396448).

Almost surely, 2^39887561 is an apocalyptic number.

It is an amenable number.

39887561 is a deficient number, since it is larger than the sum of its proper divisors (5698231).

39887561 is an equidigital number, since it uses as much as digits as its factorization.

39887561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5698230.

The product of its digits is 362880, while the sum is 47.

The square root of 39887561 is about 6315.6599813480. The cubic root of 39887561 is about 341.6744419673.

The spelling of 39887561 in words is "thirty-nine million, eight hundred eighty-seven thousand, five hundred sixty-one".