77623440 has 80 divisors (see below), whose sum is σ = 241698816. Its totient is φ = 20608000.

The previous prime is 77623421. The next prime is 77623451. The reversal of 77623440 is 4432677.

It is a tau number, because it is divible by the number of its divisors (80).

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, 66865 + ... + 68015.

Almost surely, 2^77623440 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 77623440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120849408).

77623440 is an abundant number, since it is smaller than the sum of its proper divisors (164075376).

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

77623440 is a wasteful number, since it uses less digits than its factorization.

77623440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1448 (or 1442 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 33.

The square root of 77623440 is about 8810.4165622291. The cubic root of 77623440 is about 426.5771893531.

The spelling of 77623440 in words is "seventy-seven million, six hundred twenty-three thousand, four hundred forty".