61578719 has 4 divisors (see below), whose sum is σ = 61599144. Its totient is φ = 61558296.

The previous prime is 61578701. The next prime is 61578733. The reversal of 61578719 is 91787516.

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 61578719 - 2¹⁶ = 61513183 is a prime.

It is a super-2 number, since 2×61578719² = 7583877267361922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61578719.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61578799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4697 + ... + 12050.

It is an arithmetic number, because the mean of its divisors is an integer number (15399786).

Almost surely, 2^61578719 is an apocalyptic number.

61578719 is a deficient number, since it is larger than the sum of its proper divisors (20425).

61578719 is a wasteful number, since it uses less digits than its factorization.

61578719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20424.

The product of its digits is 105840, while the sum is 44.

The square root of 61578719 is about 7847.2109057932. The cubic root of 61578719 is about 394.8906795693.

The spelling of 61578719 in words is "sixty-one million, five hundred seventy-eight thousand, seven hundred nineteen".