79221840 has 160 divisors (see below), whose sum is σ = 257233536. Its totient is φ = 20152320.

The previous prime is 79221839. The next prime is 79221841. The reversal of 79221840 is 4812297.

79221840 = 1370² + 1371² + ... + 1410².

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (79221839) and next prime (79221841).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79221841) 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 31 ways as a sum of consecutive naturals, for example, 816672 + ... + 816768.

Almost surely, 2^79221840 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 79221840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128616768).

79221840 is an abundant number, since it is smaller than the sum of its proper divisors (178011696).

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

79221840 is a wasteful number, since it uses less digits than its factorization.

79221840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237 (or 231 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 79221840 is about 8900.6651436845. The cubic root of 79221840 is about 429.4853044899.

The spelling of 79221840 in words is "seventy-nine million, two hundred twenty-one thousand, eight hundred forty".