78805620 has 36 divisors (see below), whose sum is σ = 239044260. Its totient is φ = 21014784.

The previous prime is 78805619. The next prime is 78805621. The reversal of 78805620 is 2650887.

It is an interprime number because it is at equal distance from previous prime (78805619) and next prime (78805621).

It can be written as a sum of positive squares in 2 ways, for example, as 58339044 + 20466576 = 7638^2 + 4524^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78805621) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 218725 + ... + 219084.

Almost surely, 2^78805620 is an apocalyptic number.

It is an amenable number.

78805620 is an abundant number, since it is smaller than the sum of its proper divisors (160238640).

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

78805620 is a wasteful number, since it uses less digits than its factorization.

78805620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437824 (or 437819 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 78805620 is about 8877.2529534761. The cubic root of 78805620 is about 428.7318323383.

The spelling of 78805620 in words is "seventy-eight million, eight hundred five thousand, six hundred twenty".