78493721515 has 8 divisors (see below), whose sum is σ = 102755417328. Its totient is φ = 57086342880.

The previous prime is 78493721491. The next prime is 78493721591. The reversal of 78493721515 is 51512739487.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78493721515 - 2¹⁵ = 78493688747 is a prime.

It is a super-3 number, since 3×78493721515³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 713579232 + ... + 713579341.

It is an arithmetic number, because the mean of its divisors is an integer number (12844427166).

Almost surely, 2^78493721515 is an apocalyptic number.

78493721515 is a deficient number, since it is larger than the sum of its proper divisors (24261695813).

78493721515 is a wasteful number, since it uses less digits than its factorization.

78493721515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1427158589.

The product of its digits is 2116800, while the sum is 52.

It can be divided in two parts, 78493 and 721515, that added together give a palindrome (800008).

The spelling of 78493721515 in words is "seventy-eight billion, four hundred ninety-three million, seven hundred twenty-one thousand, five hundred fifteen".