78221976 has 64 divisors (see below), whose sum is σ = 224294400. Its totient is φ = 22268928.

The previous prime is 78221971. The next prime is 78221989. The reversal of 78221976 is 67912287.

It is a super-2 number, since 2×78221976² = 12237355058689152, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78221971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58645 + ... + 59963.

It is an arithmetic number, because the mean of its divisors is an integer number (3504600).

Almost surely, 2^78221976 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 78221976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112147200).

78221976 is an abundant number, since it is smaller than the sum of its proper divisors (146072424).

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

78221976 is a wasteful number, since it uses less digits than its factorization.

78221976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1688 (or 1684 counting only the distinct ones).

The product of its digits is 84672, while the sum is 42.

The square root of 78221976 is about 8844.3188544964. The cubic root of 78221976 is about 427.6707952682.

It can be divided in two parts, 78221 and 976, that added together give a palindrome (79197).

The spelling of 78221976 in words is "seventy-eight million, two hundred twenty-one thousand, nine hundred seventy-six".