61445891 has 4 divisors (see below), whose sum is σ = 66172512. Its totient is φ = 56719272.

The previous prime is 61445887. The next prime is 61445893. The reversal of 61445891 is 19854416.

61445891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61445891 - 2² = 61445887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61445893) 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 3 ways as a sum of consecutive naturals, for example, 2363291 + ... + 2363316.

It is an arithmetic number, because the mean of its divisors is an integer number (16543128).

Almost surely, 2^61445891 is an apocalyptic number.

61445891 is a deficient number, since it is larger than the sum of its proper divisors (4726621).

61445891 is a wasteful number, since it uses less digits than its factorization.

61445891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4726620.

The product of its digits is 34560, while the sum is 38.

The square root of 61445891 is about 7838.7429476926. The cubic root of 61445891 is about 394.6065429962.

The spelling of 61445891 in words is "sixty-one million, four hundred forty-five thousand, eight hundred ninety-one".