78328290978 has 48 divisors (see below), whose sum is σ = 201139323840. Its totient is φ = 22379510736.

The previous prime is 78328290917. The next prime is 78328290983. The reversal of 78328290978 is 87909282387.

It is a happy number.

It is a super-2 number, since 2×78328290978² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11508693 + ... + 11515496.

It is an arithmetic number, because the mean of its divisors is an integer number (4190402580).

Almost surely, 2^78328290978 is an apocalyptic number.

78328290978 is an abundant number, since it is smaller than the sum of its proper divisors (122811032862).

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

78328290978 is a wasteful number, since it uses less digits than its factorization.

78328290978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23024213 (or 23024201 counting only the distinct ones).

The product of its (nonzero) digits is 24385536, while the sum is 63.

It can be divided in two parts, 783 and 28290978, that added together give a square (28291761 = 5319²).

The spelling of 78328290978 in words is "seventy-eight billion, three hundred twenty-eight million, two hundred ninety thousand, nine hundred seventy-eight".