61720704 has 80 divisors (see below), whose sum is σ = 183710670. Its totient is φ = 20570112.

The previous prime is 61720679. The next prime is 61720723. The reversal of 61720704 is 40702716.

It can be written as a sum of positive squares in only one way, i.e., 61591104 + 129600 = 7848^2 + 360^2 .

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 9 ways as a sum of consecutive naturals, for example, 7392 + ... + 13344.

Almost surely, 2^61720704 is an apocalyptic number.

61720704 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 61720704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91855335).

61720704 is an abundant number, since it is smaller than the sum of its proper divisors (121989966).

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

61720704 is an equidigital number, since it uses as much as digits as its factorization.

61720704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5979 (or 5958 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 61720704 is about 7856.2525417657. The cubic root of 61720704 is about 395.1939527122.

It can be divided in two parts, 617 and 20704, that added together give a triangular number (21321 = T₂₀₆).

The spelling of 61720704 in words is "sixty-one million, seven hundred twenty thousand, seven hundred four".