78461072978 has 54 divisors (see below), whose sum is σ = 127773976239. Its totient is φ = 36127420800.

The previous prime is 78461072953. The next prime is 78461072993. The reversal of 78461072978 is 87927016487.

It can be written as a sum of positive squares in 5 ways, for example, as 16523302849 + 61937770129 = 128543^2 + 248873^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=198067.

It is a super-2 number, since 2×78461072978² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 410790863 + ... + 410791053.

Almost surely, 2^78461072978 is an apocalyptic number.

78461072978 is a deficient number, since it is larger than the sum of its proper divisors (49312903261).

78461072978 is an equidigital number, since it uses as much as digits as its factorization.

78461072978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540 (or 271 counting only the distinct ones).

The product of its (nonzero) digits is 9483264, while the sum is 59.

The spelling of 78461072978 in words is "seventy-eight billion, four hundred sixty-one million, seventy-two thousand, nine hundred seventy-eight".