61776864 has 96 divisors (see below), whose sum is σ = 181923840. Its totient is φ = 20393856.

The previous prime is 61776833. The next prime is 61776901. The reversal of 61776864 is 46867716.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109447 + ... + 110009.

It is an arithmetic number, because the mean of its divisors is an integer number (1895040).

Almost surely, 2^61776864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61776864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90961920).

61776864 is an abundant number, since it is smaller than the sum of its proper divisors (120146976).

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

61776864 is a wasteful number, since it uses less digits than its factorization.

61776864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 709 (or 695 counting only the distinct ones).

The product of its digits is 338688, while the sum is 45.

The square root of 61776864 is about 7859.8259522715. The cubic root of 61776864 is about 395.3137794092.

It can be divided in two parts, 6177 and 6864, that added together give a triangular number (13041 = T₁₆₁).

The spelling of 61776864 in words is "sixty-one million, seven hundred seventy-six thousand, eight hundred sixty-four".