77021040 has 80 divisors (see below), whose sum is σ = 242725536. Its totient is φ = 20198400.

The previous prime is 77021029. The next prime is 77021047. The reversal of 77021040 is 4012077.

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

It is a junction number, because it is equal to n+sod(n) for n = 77020998 and 77021016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77021047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12010 + ... + 17270.

Almost surely, 2^77021040 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 77021040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121362768).

77021040 is an abundant number, since it is smaller than the sum of its proper divisors (165704496).

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

77021040 is a wasteful number, since it uses less digits than its factorization.

77021040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5338 (or 5332 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 77021040 is about 8776.1631707712. The cubic root of 77021040 is about 425.4708322948.

The spelling of 77021040 in words is "seventy-seven million, twenty-one thousand, forty".