78728642650 has 48 divisors (see below), whose sum is σ = 167377662144. Its totient is φ = 26988958080.

The previous prime is 78728642647. The next prime is 78728642653. The reversal of 78728642650 is 5624682787.

It is an interprime number because it is at equal distance from previous prime (78728642647) and next prime (78728642653).

It is a super-2 number, since 2×78728642650² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (55) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 78728642591 and 78728642600.

It is not an unprimeable number, because it can be changed into a prime (78728642653) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4047849 + ... + 4067251.

It is an arithmetic number, because the mean of its divisors is an integer number (3487034628).

Almost surely, 2^78728642650 is an apocalyptic number.

78728642650 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

78728642650 is an abundant number, since it is smaller than the sum of its proper divisors (88649019494).

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

78728642650 is a wasteful number, since it uses less digits than its factorization.

78728642650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31015 (or 31010 counting only the distinct ones).

The product of its (nonzero) digits is 9031680, while the sum is 55.

The spelling of 78728642650 in words is "seventy-eight billion, seven hundred twenty-eight million, six hundred forty-two thousand, six hundred fifty".