77221152 has 72 divisors (see below), whose sum is σ = 222666444. Its totient is φ = 25380864.

The previous prime is 77221129. The next prime is 77221153. The reversal of 77221152 is 25112277.

It can be written as a sum of positive squares in 2 ways, for example, as 73205136 + 4016016 = 8556^2 + 2004^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77221153) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19188 + ... + 22860.

Almost surely, 2^77221152 is an apocalyptic number.

77221152 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77221152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111333222).

77221152 is an abundant number, since it is smaller than the sum of its proper divisors (145445292).

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

77221152 is a wasteful number, since it uses less digits than its factorization.

77221152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3762 (or 3751 counting only the distinct ones).

The product of its digits is 1960, while the sum is 27.

The square root of 77221152 is about 8787.5566570009. The cubic root of 77221152 is about 425.8389922523.

The spelling of 77221152 in words is "seventy-seven million, two hundred twenty-one thousand, one hundred fifty-two".