78172620 has 48 divisors (see below), whose sum is σ = 220909920. Its totient is φ = 20653056.

The previous prime is 78172597. The next prime is 78172621. The reversal of 78172620 is 2627187.

It is a super-2 number, since 2×78172620² = 12221917035328800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78172621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 564 + ... + 12516.

It is an arithmetic number, because the mean of its divisors is an integer number (4602290).

Almost surely, 2^78172620 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 78172620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110454960).

78172620 is an abundant number, since it is smaller than the sum of its proper divisors (142737300).

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

78172620 is a wasteful number, since it uses less digits than its factorization.

78172620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12074 (or 12072 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 33.

The square root of 78172620 is about 8841.5281484594. The cubic root of 78172620 is about 427.5808266857.

The spelling of 78172620 in words is "seventy-eight million, one hundred seventy-two thousand, six hundred twenty".