78391622650 has 36 divisors (see below), whose sum is σ = 160268769486. Its totient is φ = 28506042400.

The previous prime is 78391622599. The next prime is 78391622653. The reversal of 78391622650 is 5622619387.

It can be written as a sum of positive squares in 3 ways, for example, as 52919781849 + 25471840801 = 230043^2 + 159599^2 .

It is a super-2 number, since 2×78391622650² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78391622594 and 78391622603.

It is not an unprimeable number, because it can be changed into a prime (78391622653) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 6472597 + ... + 6484696.

Almost surely, 2^78391622650 is an apocalyptic number.

78391622650 is an abundant number, since it is smaller than the sum of its proper divisors (81877146836).

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

78391622650 is a wasteful number, since it uses less digits than its factorization.

78391622650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12957327 (or 12957311 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 49.

The spelling of 78391622650 in words is "seventy-eight billion, three hundred ninety-one million, six hundred twenty-two thousand, six hundred fifty".