79191840 has 384 divisors, whose sum is σ = 321753600. Its totient is φ = 16257024.

The previous prime is 79191821. The next prime is 79191841. The reversal of 79191840 is 4819197.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79191841) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2140302 + ... + 2140338.

It is an arithmetic number, because the mean of its divisors is an integer number (837900).

Almost surely, 2^79191840 is an apocalyptic number.

79191840 is a gapful number since it is divisible by the number (70) 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 79191840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160876800).

79191840 is an abundant number, since it is smaller than the sum of its proper divisors (242561760).

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

79191840 is a wasteful number, since it uses less digits than its factorization.

79191840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 39.

The square root of 79191840 is about 8898.9797167990. The cubic root of 79191840 is about 429.4310846524.

The spelling of 79191840 in words is "seventy-nine million, one hundred ninety-one thousand, eight hundred forty".