61720878 has 8 divisors (see below), whose sum is σ = 123441768. Its totient is φ = 20573624.

The previous prime is 61720871. The next prime is 61720889. The reversal of 61720878 is 87802716.

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

61720878 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61720871) 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, 5143401 + ... + 5143412.

It is an arithmetic number, because the mean of its divisors is an integer number (15430221).

Almost surely, 2^61720878 is an apocalyptic number.

61720878 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61720878 is a wasteful number, since it uses less digits than its factorization.

61720878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10286818.

The product of its (nonzero) digits is 37632, while the sum is 39.

The square root of 61720878 is about 7856.2636157400. The cubic root of 61720878 is about 395.1943240824.

The spelling of 61720878 in words is "sixty-one million, seven hundred twenty thousand, eight hundred seventy-eight".