77221700 has 72 divisors (see below), whose sum is σ = 178634400. Its totient is φ = 28892160.

The previous prime is 77221691. The next prime is 77221709. The reversal of 77221700 is 712277.

It is an interprime number because it is at equal distance from previous prime (77221691) and next prime (77221709).

It is a self number, because there is not a number n which added to its sum of digits gives 77221700.

It is not an unprimeable number, because it can be changed into a prime (77221709) 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, 184091 + ... + 184509.

Almost surely, 2^77221700 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 77221700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89317200).

77221700 is an abundant number, since it is smaller than the sum of its proper divisors (101412700).

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

77221700 is a wasteful number, since it uses less digits than its factorization.

77221700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549 (or 542 counting only the distinct ones).

The product of its (nonzero) digits is 1372, while the sum is 26.

The square root of 77221700 is about 8787.5878373988. The cubic root of 77221700 is about 425.8399995723.

Adding to 77221700 its reverse (712277), we get a palindrome (77933977).

The spelling of 77221700 in words is "seventy-seven million, two hundred twenty-one thousand, seven hundred".