77641980 has 192 divisors, whose sum is σ = 255897600. Its totient is φ = 17521920.

The previous prime is 77641973. The next prime is 77641981. The reversal of 77641980 is 8914677.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77641981) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 2504565 + ... + 2504595.

It is an arithmetic number, because the mean of its divisors is an integer number (1332800).

Almost surely, 2^77641980 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 77641980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127948800).

77641980 is an abundant number, since it is smaller than the sum of its proper divisors (178255620).

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

77641980 is a wasteful number, since it uses less digits than its factorization.

77641980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101 (or 73 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 42.

The square root of 77641980 is about 8811.4686630550. The cubic root of 77641980 is about 426.6111486465.

The spelling of 77641980 in words is "seventy-seven million, six hundred forty-one thousand, nine hundred eighty".