77720460 has 48 divisors (see below), whose sum is σ = 219206400. Its totient is φ = 20574144.

The previous prime is 77720459. The next prime is 77720471. The reversal of 77720460 is 6402777.

It is a happy number.

It is a super-2 number, since 2×77720460² = 12080939805223200, which contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 3681 + ... + 12999.

It is an arithmetic number, because the mean of its divisors is an integer number (4566800).

Almost surely, 2^77720460 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 77720460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109603200).

77720460 is an abundant number, since it is smaller than the sum of its proper divisors (141485940).

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

77720460 is a wasteful number, since it uses less digits than its factorization.

77720460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9470 (or 9468 counting only the distinct ones).

The product of its (nonzero) digits is 16464, while the sum is 33.

The square root of 77720460 is about 8815.9208254158. The cubic root of 77720460 is about 426.7548388198.

The spelling of 77720460 in words is "seventy-seven million, seven hundred twenty thousand, four hundred sixty".