78459012 has 36 divisors (see below), whose sum is σ = 209994876. Its totient is φ = 24614400.

The previous prime is 78459011. The next prime is 78459019. The reversal of 78459012 is 21095487.

It can be written as a sum of positive squares in 2 ways, for example, as 62346816 + 16112196 = 7896^2 + 4014^2 .

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

It is a super-2 number, since 2×78459012² = 12311633128032288, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (78459011) 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, 63489 + ... + 64712.

It is an arithmetic number, because the mean of its divisors is an integer number (5833191).

Almost surely, 2^78459012 is an apocalyptic number.

It is an amenable number.

78459012 is an abundant number, since it is smaller than the sum of its proper divisors (131535864).

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

78459012 is a wasteful number, since it uses less digits than its factorization.

78459012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128228 (or 128223 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 78459012 is about 8857.7091846594. The cubic root of 78459012 is about 428.1023498202.

The spelling of 78459012 in words is "seventy-eight million, four hundred fifty-nine thousand, twelve".