61643889 has 16 divisors (see below), whose sum is σ = 91587840. Its totient is φ = 40977360.

The previous prime is 61643867. The next prime is 61643891. The reversal of 61643889 is 98834616.

It is not a de Polignac number, because 61643889 - 2⁷ = 61643761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61643899) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6799 + ... + 13019.

It is an arithmetic number, because the mean of its divisors is an integer number (5724240).

Almost surely, 2^61643889 is an apocalyptic number.

It is an amenable number.

61643889 is a deficient number, since it is larger than the sum of its proper divisors (29943951).

61643889 is a wasteful number, since it uses less digits than its factorization.

61643889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6597 (or 6591 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 61643889 is about 7851.3622384908. The cubic root of 61643889 is about 395.0299373774.

The spelling of 61643889 in words is "sixty-one million, six hundred forty-three thousand, eight hundred eighty-nine".