61645987 has 8 divisors (see below), whose sum is σ = 66669120. Its totient is φ = 56663040.

The previous prime is 61645981. The next prime is 61646041. The reversal of 61645987 is 78954616.

61645987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 61645987 - 2³ = 61645979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61645981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6814 + ... + 13027.

It is an arithmetic number, because the mean of its divisors is an integer number (8333640).

Almost surely, 2^61645987 is an apocalyptic number.

61645987 is a deficient number, since it is larger than the sum of its proper divisors (5023133).

61645987 is a wasteful number, since it uses less digits than its factorization.

61645987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20093.

The product of its digits is 362880, while the sum is 46.

The square root of 61645987 is about 7851.4958447419. The cubic root of 61645987 is about 395.0344188349.

The spelling of 61645987 in words is "sixty-one million, six hundred forty-five thousand, nine hundred eighty-seven".