78561630 has 128 divisors (see below), whose sum is σ = 241781760. Its totient is φ = 17781120.

The previous prime is 78561589. The next prime is 78561653. The reversal of 78561630 is 3616587.

78561630 is a `hidden beast` number, since 7 + 8 + 5 + 616 + 30 = 666.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 372225 + ... + 372435.

It is an arithmetic number, because the mean of its divisors is an integer number (1888920).

Almost surely, 2^78561630 is an apocalyptic number.

78561630 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 78561630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120890880).

78561630 is an abundant number, since it is smaller than the sum of its proper divisors (163220130).

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

78561630 is a wasteful number, since it uses less digits than its factorization.

78561630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431 (or 425 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 78561630 is about 8863.4998730750. The cubic root of 78561630 is about 428.2889095155.

The spelling of 78561630 in words is "seventy-eight million, five hundred sixty-one thousand, six hundred thirty".