77321420 has 72 divisors (see below), whose sum is σ = 180986400. Its totient is φ = 27723520.

The previous prime is 77321411. The next prime is 77321429. The reversal of 77321420 is 2412377.

It is an interprime number because it is at equal distance from previous prime (77321411) and next prime (77321429).

It is a self number, because there is not a number n which added to its sum of digits gives 77321420.

It is not an unprimeable number, because it can be changed into a prime (77321429) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 215201 + ... + 215559.

It is an arithmetic number, because the mean of its divisors is an integer number (2513700).

Almost surely, 2^77321420 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 77321420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90493200).

77321420 is an abundant number, since it is smaller than the sum of its proper divisors (103664980).

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

77321420 is a wasteful number, since it uses less digits than its factorization.

77321420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479 (or 466 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 26.

The square root of 77321420 is about 8793.2599188242. The cubic root of 77321420 is about 426.0232231089.

Adding to 77321420 its reverse (2412377), we get a palindrome (79733797).

The spelling of 77321420 in words is "seventy-seven million, three hundred twenty-one thousand, four hundred twenty".