78377820 has 96 divisors (see below), whose sum is σ = 237904128. Its totient is φ = 19203072.

The previous prime is 78377809. The next prime is 78377833. The reversal of 78377820 is 2877387.

It is a super-2 number, since 2×78377820² = 12286165335904800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42967 + ... + 44753.

It is an arithmetic number, because the mean of its divisors is an integer number (2478168).

Almost surely, 2^78377820 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 78377820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118952064).

78377820 is an abundant number, since it is smaller than the sum of its proper divisors (159526308).

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

78377820 is a wasteful number, since it uses less digits than its factorization.

78377820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1859 (or 1857 counting only the distinct ones).

The product of its (nonzero) digits is 131712, while the sum is 42.

The square root of 78377820 is about 8853.1248720438. The cubic root of 78377820 is about 427.9546273269.

It can be divided in two parts, 78377 and 820, that added together give a palindrome (79197).

The spelling of 78377820 in words is "seventy-eight million, three hundred seventy-seven thousand, eight hundred twenty".