77887221 has 8 divisors (see below), whose sum is σ = 107199744. Its totient is φ = 50249760.

The previous prime is 77887219. The next prime is 77887231. The reversal of 77887221 is 12278877.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 77887221 - 2¹ = 77887219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77887211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 418656 + ... + 418841.

It is an arithmetic number, because the mean of its divisors is an integer number (13399968).

Almost surely, 2^77887221 is an apocalyptic number.

It is an amenable number.

77887221 is a deficient number, since it is larger than the sum of its proper divisors (29312523).

77887221 is a wasteful number, since it uses less digits than its factorization.

77887221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 837531.

The product of its digits is 87808, while the sum is 42.

The square root of 77887221 is about 8825.3737031357. The cubic root of 77887221 is about 427.0598431266.

The spelling of 77887221 in words is "seventy-seven million, eight hundred eighty-seven thousand, two hundred twenty-one".