77721600 has 312 divisors, whose sum is σ = 292516992. Its totient is φ = 18022400.

The previous prime is 77721599. The next prime is 77721617. The reversal of 77721600 is 612777.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3379189 + ... + 3379211.

Almost surely, 2^77721600 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 77721600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146258496).

77721600 is an abundant number, since it is smaller than the sum of its proper divisors (214795392).

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

77721600 is a wasteful number, since it uses less digits than its factorization.

77721600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 4116, while the sum is 30.

The square root of 77721600 is about 8815.9854809318. The cubic root of 77721600 is about 426.7569253494.

The spelling of 77721600 in words is "seventy-seven million, seven hundred twenty-one thousand, six hundred".