61720064 has 80 divisors (see below), whose sum is σ = 149374368. Its totient is φ = 24870912.

The previous prime is 61720019. The next prime is 61720079. The reversal of 61720064 is 46002716.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60422 + ... + 61434.

Almost surely, 2^61720064 is an apocalyptic number.

61720064 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61720064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74687184).

61720064 is an abundant number, since it is smaller than the sum of its proper divisors (87654304).

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

61720064 is a wasteful number, since it uses less digits than its factorization.

61720064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1055 (or 1039 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 61720064 is about 7856.2118097719. The cubic root of 61720064 is about 395.1925867470.

The spelling of 61720064 in words is "sixty-one million, seven hundred twenty thousand, sixty-four".