78763581 has 12 divisors (see below), whose sum is σ = 122521308. Its totient is φ = 48469824.

The previous prime is 78763577. The next prime is 78763589. The reversal of 78763581 is 18536787.

78763581 is a `hidden beast` number, since 7 + 8 + 7 + 63 + 581 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 32387481 + 46376100 = 5691^2 + 6810^2 .

It is not a de Polignac number, because 78763581 - 2² = 78763577 is a prime.

It is a super-2 number, since 2×78763581² = 12407403383887122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78763589) 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, 336480 + ... + 336713.

It is an arithmetic number, because the mean of its divisors is an integer number (10210109).

Almost surely, 2^78763581 is an apocalyptic number.

It is an amenable number.

78763581 is a deficient number, since it is larger than the sum of its proper divisors (43757727).

78763581 is a wasteful number, since it uses less digits than its factorization.

78763581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 673212 (or 673209 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 78763581 is about 8874.8848443233. The cubic root of 78763581 is about 428.6555828553.

The spelling of 78763581 in words is "seventy-eight million, seven hundred sixty-three thousand, five hundred eighty-one".