78399440002 has 16 divisors (see below), whose sum is σ = 127766008440. Its totient is φ = 35864140032.

The previous prime is 78399439991. The next prime is 78399440003. The reversal of 78399440002 is 20004499387.

It is a happy number.

It is a Cunningham number, because it is equal to 279999²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 11597351481 + 66802088521 = 107691^2 + 258461^2 .

It is a super-2 number, since 2×78399440002² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78399440003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13339377 + ... + 13345252.

Almost surely, 2^78399440002 is an apocalyptic number.

78399440002 is a deficient number, since it is larger than the sum of its proper divisors (49366568438).

78399440002 is a wasteful number, since it uses less digits than its factorization.

78399440002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26684757.

The product of its (nonzero) digits is 435456, while the sum is 46.

The spelling of 78399440002 in words is "seventy-eight billion, three hundred ninety-nine million, four hundred forty thousand, two".