77721264 has 60 divisors (see below), whose sum is σ = 218245456. Its totient is φ = 25819776.

The previous prime is 77721257. The next prime is 77721277. The reversal of 77721264 is 46212777.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52989 + ... + 54435.

Almost surely, 2^77721264 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 77721264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109122728).

77721264 is an abundant number, since it is smaller than the sum of its proper divisors (140524192).

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

77721264 is a wasteful number, since it uses less digits than its factorization.

77721264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1834 (or 1825 counting only the distinct ones).

The product of its digits is 32928, while the sum is 36.

The square root of 77721264 is about 8815.9664246185. The cubic root of 77721264 is about 426.7563103744.

The spelling of 77721264 in words is "seventy-seven million, seven hundred twenty-one thousand, two hundred sixty-four".